Manchester United manager Ole Gunnar Solskjaer’s happiness at making it through to the FA Cup fourth round was tinged by disappointment at his much-changed side’s display against Watford.

Having fallen to a galling loss to rivals Manchester City in Wednesday’s Carabao Cup semi-final, Scott McTominay’s early header secured a 1-0 win against Sky Bet Championship opposition in Saturday evening’s third-round encounter.

United flew out of the blocks at an empty Old Trafford but dropped off markedly, with the nine players brought into the side leading to a lack of fluency and unconvincing display.

“Very happy to get through,” Solskjaer said. “We started very brightly.

“I expected it to be other way round – that we needed 15-20 minutes to get going and find our rhythm.

“But after a very good start we lost our shape, we lost too many balls.

“We lost it easily. It was like we started making difficult decisions to try and complicate things and maybe show the manager that ‘I want to play in the next game’.

“I know they’re good players so they didn’t have to do that, but we’re through. That’s the main thing.”

Donny Van De Beek, Brandon Williams and Jesse Lingard were among the alterations, with Dean Henderson and McTominay the only players retaining a starting spot from the City loss.

The latter proved the difference on Saturday evening, when leading United out as captain for the first time.

“He’s got great character, good attitude,” Solskjaer said of academy graduate McTominay. “He comes in every day, does the right things, lives his life properly, wants to be the best he can be and he’s not afraid to be vocal.

“He always, always goes out there to give his best. Never shirks a tackle. Nothing.

“He’s got everything a leader has to have, so I just wanted to test him today how he reacted because he always done that anyway.

“But I gave him the armband to see if there was any change in him but luckily there wasn’t.”

On a night of few highlights, the main concern was the blow that forced Eric Bailly off towards the end of the first half.

Having been hit in the back of the head when goalkeeper Henderson was clearing a ball, Solskjaer said when asked for an update: “I honestly can’t tell you.

“I think he got a good whack. I don’t think it’s concussion. I think it’s his neck, which is sore.

“Hopefully a muscle injury but we’ll have to check him tomorrow and fingers crossed he won’t be out for too long.”

Solskjaer will have to check on Bailly ahead of Tuesday’s trip to Burnley along with Paul Pogba, Victor Lindelof and Luke Shaw after the United boss confirmed the trio missed out on the squad through injury.

Watford return to action at home to Huddersfield in the Championship next weekend after putting in a performance that pleased recently-appointed boss Xisco Munoz.

“I’m very proud of our players,” he said after his third match in charge of the Hornets. “This is our style.

“I know we have little details to improve. We know we have a very good team against us.

“The guys give us very good intensity, with very good tactics.

“Our team is growing up and it’s important we believe in our team.”