72' Mount comes on to the field to replace Havertz in the final third.
71' Werner is withdrawn after an underwhelming game and is replaced by Abraham.
71' Chilwell swings a cross-field pass to James in space. He takes the ball out of the air and shoots first time, but Fred is there with a vital block.
70' Cavani is played into space down the right flank, but he lifts a timid cross into the middle that Mendy claims with ease.
62' James battles with Rashford for possession on the edge of the Chelsea box, and the defender wins the duel and possession.
60' CHANCE! James sends a dangerous ball towards the back post that evades the head of Havertz and somehow Pulisic fails to connect with an outstretched boot on the slide. Close for the Blues.
59' CLOSE! Cavani almost scores with his first touch for United. He sticks out a boot to flick a cross from Shaw towards the near post. It threatens the Chelsea goal, but clips the side-netting on its way wide.
58' Cavani (33y 253d) is the oldest player to make his Premier League debut for Man Utd since Zlatan Ibrahimovic (34y 316d) in August 2016.
58' James makes way for Cavani, who makes his United bow.
58' Pobga replaces Mata for the home side in the middle of the park.
58' United keep the attack alive and Shaw wins a corner down the left flank.
58' Substitution Daniel James Edinson Roberto Cavani Gómez
58' Substitution Juan Manuel Mata García Paul Pogba
57' Fernandes releases Rashford forward down the left inside channel. He tries to carve out space for a strike, but he is forced across the pitch and fails to muster an effort at goal.
53' Pulisic and Havertz combine to pick out Werner in the box, but the German sees his low strike blocked by Maguire.
51' United win a corner down the left and Mata sees his cross cleared as far as Fred. The midfielder goes for a strike at goal, but it is deflected wide. Mata tries to keep it alive, only to be flagged offside.
49' Pulisic runs down the left flank and reaches the byline. He goes down under pressure from Lindelof, but there is no appeal for a penalty.
48' Fernandes releases the run of James down the left, but the winger runs straight into Azpilicueta and loses possession.
46' We're back underway at Old Trafford.
45' + 1' HALF-TIME: MANCHESTER UNITED 0-0 CHELSEA
45' + 1' Wan-Bissaka fires a low cross in from the right flank that is deflected. Mendy eases the pressure on his defence by claiming the delivery.
45' + 1' Havertz pulls back Fred on a run through the middle and goes into the book.
45' Chelsea are attempting to take the sting out of the game before the half. They lost their shape briefly after edging the first period and it almost cost them.
43' Chelsea clear their lines from the resulting corner and Rashford returns to the field albeit slightly gingerly.
42' VAR! There is a check on the challenge on Rashford by Silva, but the officials deem that it was not a penalty.
42' Rashford is down in pain after the strike. He fell amid contact from Silva, but there was no action taken by the referee. The England man receives treatment on the field.
41' SAVE! Mendy has to be alert to divert a strike from Mata away from goal. The Spaniard latches on to a loose ball following a surge from Rashford. Mata curls a left-footed shot towards the bottom-left corner, but the Chelsea keeper was equal to the threat.
40' Chilwell floats a free-kick into the box from the right flank. Maguire rises above Azpilicueta to clear the danger, although the Spaniard claims he is pulled down by the United defender.
39' Shaw pulls back James on the charge down the right flank. He goes into the book, while Chelsea have a free-kick in a dangerous position.
37' The contest is beginning to open up as chances are coming at both ends of the pitch. Neither team has displayed a clinical edge yet.
35' SAVE! Mata releases the run of Rashford through on goal and the forward only has Mendy to beat. He powers a low strike towards the net on his right foot, but the Chelsea keeper sticks out a boot and diverts it wide of the left post. A solid stop.
34' WIDE! Fred loses possession in the United half and it allows Pulisic to charge forward. He powers a low strike towards goal that Lindelof diverts wide of the target. Chelsea are finding their rhythm.
33' CHANCE! Pulisic collects on the left flank and beats the challenge of McTominay, but he sends his low strike on his right foot straight at De Gea.
31' SAVE! Chelsea clear their lines from back-to-back corners, but space opens up for Fernandes to strike. The Portugues lines up an effort from 25 yards, but it's straight at Mendy.
30' CLOSE! Mendy almost drags the ball into his own net, misplacing his offload towards Silva. It's only a corner for United, but it could have been so much worse for Chelsea.
29' McTominay takes a touch on the edge of the box and shapes to shoot. Pulisic tracks him and blocks the strike from the Scot.
28' James tries to catch out De Gea looking at the line of players rather than the ball, but the Spaniard gets back across to his right to make a comfortable save.
25' United win a corner down the right flank and Maguire rises to meet the delivery from James, but Zouma clears with authority in the box.
23' Lindelof is on the spot at the back for United twice in quick succession, sending passes from Jorginho and Pulisic towards Werner away from danger.
21' Havertz tries to release Chilwell down the left flank, but Wan-Bissaka fends off the full-back and earns a goal-kick.
19' Chelsea apply pressure as Azpilicueta floats a cross-field pass down the left flank. Chilwell wins a corner off the body of Wan-Bissaka. The Blues are beginning to threaten.
17' Shaw has to be alert to clear away from Havertz, but he concedes a corner in the process.
16' Rashford takes a knock to the back of the head from Zouma. He has a word with the referee after the fact.
14' Jorginho takes a step past Fernandes before being brought down by the Portuguese. The first real challenge of the game.
11' Both sides are containing the other with solid pressing. There are not many easy passes out there.
10' Maguire floats a ball over the top looking for the run of James, but the Welshman is flagged offside as he collects.
7' Chilwell has to work back towards his own goal to clear his lines, although he can only find touch. Defenders have to be careful tonight in the conditions.
5' Pulisic has a dart into the United box, but he gets halted by a well-timed challenge by Wan-Bissaka.
3' Both teams are trying to get their foot on the ball in the early stages amid heavy rain at Old Trafford.
1' We're underway at Old Trafford.