119 min: Henderson tries to make things a little interesting with a daredevil dribble inside his own box, and gets away with it.
117 min: Keep-ball from United, before a pass from McTominay and a harmless shot at Fabianski by Martial.
114 min: West Ham are trying to exert some pressure … and a Johnson cross finds Benrahma, who flicks a header straight at Henderson. I think he was offside anyway. Itâ€™s the nearest thing they have really had to a chance all night.
112 min: West Ham sub the sub, Odubeko, for Lanzini. The youngster barely had a kick.
111 min: â€œWell, at least we can say that no live spectators suffered in the playing of this game. And hopefully everyone watching at home was wearing masks. Over their eyes,â€ writes Justin Kavanagh.
109 min: A West Ham move breaks down and Cavani charges into open space, but he sends Rashford too wide with a sloppy pass.
107 min: I think West Ham look pretty shot, so United just need to be sensible now.
Peeeep! Into the final 15
Unless West Ham can salvage pens …
Half time in extra time: Manchester United 1-0 West Ham
Iâ€™ll not lie, we could have all done with that goal coming a little bit earlier. But it was a decent drive from McTominay, who has now scored seven this season, so letâ€™s drink the goodness in.
105 min: â€œGreat ambition shown by Moyes with his plan for West Ham to score no goals and lose this game in extra time,â€ says Robert Speed.
103 min: From a very similar United attack to the one that eventually brought the goal, Fernandes uncharacteristically bodges a pass for Martial and it runs behind.
101 min: What do West Ham have left in the tank? Benrahma tries to play Soucek in but canâ€™t quite find his man.
Goal! Manchester United 1-0 West Ham (McTominay 97)
And … wow … a goal! A four-on-four counter from United, with the game becoming increasingly stretched, seems to have run adrift when a Fred cross is headed away. But Rashford nudges the ball into McTominayâ€™s path with a deftness and subtlety quite out of step with the night, and the sub batters the ball low past Fabianski!
97 min: Amad Diallo is warming up. Iâ€™d like to see him get 15 minutes. That might lift this a bit.
95 min: United still making most of the running here, with West Ham possibly tiring a bit. Nobody will have wanted 120 here, not with this schedule.
93 min: Kari Tulinius writes inâ€“
â€œThis game is fascinatingly dull. It might even rival the infamous match between Switzerland and Ukraine in the 2nd round of the 2006 World Cup. Iâ€™m losing my will to live, but I also canâ€™t tear my eyes away from this travesty.â€
I watched that game in a fan park next to the old Olympic Stadium in Munich amid an absolutely *almighty* thunderstorm, so at least that was memorable.
United will bring on Telles and Williams at full-back for Shaw and Wan-Bissaka.
I have a possibly unpopular opinion, which is that â€“ with some very notable exceptions â€“ football has really not been very good at all since around early December. This hasnâ€™t disabused me of the idea.
Full-time: Manchester United 0-0 West Ham â€“ extra time to be played
West Ham canâ€™t quite do anything with the corner, so we are condemned.
90 min: Fabianski clutches a Telles cross. Thatâ€™s it, thatâ€™s the update.
89 min: Benrahma is on for West Ham, replacing Fornals. But I fear we are doomed to an extra 30 minutes of possibly the dullest game Iâ€™ve seen all season â€“ and look, I attended both Fulham-Brighton fixtures.
85 min: Weâ€™re up to first half-hour levels of Man Utd domination now, without a goal looking especially likely. Maybe this will jinx it.
82 min: Martial bullet-heads a decent Telles cross wide at the near post. Well wide, but still one of the more exciting and dynamic moments weâ€™ve seen.
81 min: At least Fernandes looks bright, and he sees a shot deflected over. Contrast that with poor old Van de Beek. Will something happen from this corner? Not really.
79 min: This isnâ€™t a very good advert for the 2020-21 football season, letâ€™s be honest.
75 min: Fernandes instantly sprays a beautiful pass down the line for Greenwood, but United canâ€™t quite fashion a shooting chance out of the resulting flurry and the rock-solid Dawson clears.
73 min: It comes to nothing, but here are two United subs. Van de Beek looks over to the touchline forlornly. He does indeed go off, and so does Matic â€“ on come Fernandes and McTominay. Can someone *please* save us from extra time now?
70 min: Dawson does very well to fling himself across and head away a ball from Fred after a good run from the midfielder. I think Fernandes is readying himself, but not before this West Ham corner â€“ which came after Henderson tipped over a skied clearance from his own man, Wan-Bissaka.
68 min: A 3 vs 3 break for West Ham but … ohhhh … Fornals fluffs the final pass when they had a player over, and Lindelof intervenes.
67 min: Fredericks takes on Telles and gets to the line, but his low cross is snicked away from Soucek.
66 min: â€œI feel Fred gets a bit more stick than he deserves,â€ offers Dean Kinsella. â€œAlright, heâ€™s not the most creative midfielder but does a lot of the donkey work breaking up opponentâ€™s attacks. Not glamorous but necessary especially against the tough hombres playing for the Hammers.â€
64 min: A scruffy spell. And not exactly the first. One of those games that youâ€™d quite like to get done and dusted but, at the same time, you want to go all the way to pens so at not to feel short-changed.
61 min: West Ham build the play well before Henderson claims Johnsonâ€™s cross. They have looked much more comfortable in the new system.
59 min: … which is scrappily cleared by Unitedâ€™s defence.
58 min: That good Rashford chance apart, little has happened yet in this half. West Ham arenâ€™t sitting off quite at much as they were, though, and earn another corner …
55 min: And now, indeed, a fourth West Ham sub. Yarmolenko, who had been struggling, comes off and the young former United striker Ademipo Odubeko is on. Narrative incoming … ?
54 min: Best chance of the game there for Rashford, who is alone at the back post after a Greenwood cross evades Martial but faced rapidly by the excellent Fabianski, who spreads himself and blocks.
53 min: Incidentally, I think Diopâ€™s replacement by Fredericks was as a concussion sub. So West Ham can use another.
51 min: It is snowing lightly at Old Trafford. Best thing thatâ€™s happened yet!
50 min: Johnson has started well down that left side and a strong run sees Maguire forced to cut out his low cross.
49 min: The longer this goes on, the more tempted Solsjkaer will be to haul on Fernandes and/or Cavani.
46 min: West Ham are now playing with a back three â€“ or five, whichever way you look at it. Ryan Fredericks has also come on, replacing the replacement Diop, so he and Johnson will be wing-backs.
Peeeeep! Second half underway
Man Utd kick off, after being left in the cold by West Ham for a fair few minutes, and weâ€™re surely in for a better half this time. The visitors make a change â€“ Ben Johnson on for Bowen.
The second half is three or four minutes away â€“ donâ€™t go anywhere …
There was a real live cupset earlier. Richard Jolly was at Burnley 0-2 Bournemouth for us:
Neil Carter writes: â€œTerrible game, just terrible. I have seen a fair few mediocre midfielders play for Man Utd over the last 40 years but Fred has to be up there as one of the most pointless. I just donâ€™t get what heâ€™s good at. Poor Donny, playing with him and Matic, devoid of confidence and lacking match fitness, I hope things improve for him he looks bewildered at times. Diallo on in the second half please!â€
Half-time: Manchester United 0-0 West Ham
Not the best. West Ham lost Ogbonna early on, in the process of snuffing out a Martial chance, but otherwise a fine save by Fabianski from a deflected Lindelof header was the best of the action. The Hammers livened up in the final 10-15 minutes of the half without creating much. All to play for, and hopefully it opens up a bit.
45 min: Coufal blocks from Martial but Van de Beek, who teed him up, is offside. Weâ€™ll see three added minutes.
43 min: West Hamâ€™s Good Spell continues, with one cross from the right going begging. No real chances created, but they have drawn Unitedâ€™s sting.
40 min: Rice bustles down the left but doesnâ€™t see a potential pass to Yarmolenko and the ball ends up with Henderson. Better from West Ham in the last six or seven minutes though.
39 min: Martial is OK, I think. Heâ€™s rubbing his forehead but is up and about. Diop actually seemed the worst hit but looks set to carry on too.
38 min: Itâ€™s helped on at the near post and then Martial heads away *ever so bravely* from the onrushing Diop, taking a whack in the head for his trouble as they challenge. Both men go down. That was painful and this doesnâ€™t look great. Is this going to be a concussion issue?
36 min: Bowen takes too long over a West Ham counter and Van de Beek â€“ heâ€™s playing! â€“ pops back to sort him out. Moment later the Hammers earn a corner …
34 min: Nearly something for them there, though, Yarmolenko helping the ball through to Bowen. The forward would be in on goal if it wasnâ€™t for a rapid recovery from Telles.