Manchester United edged a nervy encounter with Russian minnows FC Rostov at Old Trafford to reach the Europa League quarter-finals with a 2-1 aggregate victory.

Juan Mata got the decisive goal for United when he stabbed in from Zlatan Ibrahimovic's flick, but Rostov threatened to take the game to extra time and Sergio Romero made two good saves late on.

The United goalkeeper first kept out Sardar Azmoun's flicked header before thumping away Christian Noboa's free-kick.

It was a largely frustrating night for United, who dominated for large periods without really threatening and also lost midfielder Paul Pogba to a hamstring injury.

Their best chances before the goal came in the first half, when Henrikh Mkhitaryan shot wide when one-on-one and Ibrahimovic twice hit the post.

United will find out on Friday who they will play in the quarter-finals, with the draw taking place at 12:00 GMT.

Can United go all the way?

The Europa League is the only major trophy that has so far eluded United, but winning the competition is not just about collecting another piece of silverware.

With a guaranteed place in next season's Champions League for the winners, United, who are sixth in the Premier League, would not have to rely solely on finishing in the top four.

Mourinho showed he was in no mood to take any chances by naming a strong side against Rostov, with Ibrahimovic - who is serving a three-match domestic ban - reinstated.

The Swedish striker, absent from Monday's 1-0 FA Cup quarter-final defeat at Chelsea, looked fresh and hungry from the outset, hitting the post from close range early on before cracking another effort against the upright before the break.

Those chances aside, United struggled to find a way through a packed Rostov defence and it looked as though they would have to rely on the goal they scored in Russia to scrape into the quarter-finals.

An inventive bit of skill by Ibrahimovic helped make the breakthrough in the end, but United know they will need to improve if they are to go all the way in the competition, with better sides than Rostov waiting.

Injuries mounting for United

It was a victory that came at a cost for Mourinho as he lost Pogba and Daley Blind to injury.

Midfielder Pogba has come in for criticism recently, but Mourinho clearly sees the £89m midfielder as a crucial part of his side.

The France international was making his 41st appearance of the season for United but has rarely dominated a game, and he was largely a peripheral figure here before pulling up with an apparent hamstring injury early in the second half. He will miss Sunday's Premier League game at Middlesbrough.

Mourinho was then forced into another change, and a reshuffle at the back, when defender Blind went off midway through the half with suspected concussion.

With a congested fixture list caused by United battling for Europa League success and a place in the Premier League top four, Mourinho will hope neither player is out for an extended period.

Man of the match - Marcos Rojo

What they said

Manchester United boss Jose Mourinho, speaking to BT Sport: "We were afraid of extra time. It was a difficult game.

"We have lots of enemies. Normally the enemies should be Rostov but we have a lot of enemies. It's difficult to play Monday with 10 men, it's difficult to play now, it's difficult to play 12 o'clock on Sunday. We have a lot of enemies.

"A lot of people might say we should have scored more goals. But a lot of things are going against us. The boys are amazing boys. We will probably lose the game on Sunday. Fatigue has a price.

"I will remember forever when I spoke to the Uefa delegate in Rostov. He told me if any of our players gets injured, the insurance paid. Whoever decided the Monday and Sunday games probably thinks the same way."

What next?

United are next in action when they travel to Middlesbrough in the Premier League on Sunday (12:00 GMT).