MANCHESTER, England - Jose Mourinho said "enemies" were undermining his team after Paul Pogba was injured in a 1-0 victory over Rostov on Thursday that sent Manchester United into the Europa League quarterfinals.

Pogba hobbled off with a hamstring injury early in the second half of the 1-0 win, which completed a 2-1 aggregate last-16 success over the Russian side.

United also played on Monday, losing 1-0 at Chelsea in the FA Cup quarterfinals after going down to 10 men, and travels to Middlesbrough in the Premier League on Sunday.

In an apparent reference to the match schedulers, Mourinho complained: "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."

Mourinho expects to lose Pogba for around three weeks, ruling him out of the Boro trip and France's forthcoming games against Luxembourg and Spain.

Asked if Pogba is facing a three-week absence, Mourinho replied: "Yeah. I don't know for sure, but for sure, no Middlesbrough and no national team."

Warming to his theme, Mourinho suggested the compression of matches meant United was likely to lose at struggling Middlesbrough, which on Thursday sacked manager Aitor Karanka, the Portuguese's former Real Madrid assistant.

"A lot of people might say we should have scored more goals. But a lot of things are going against us," Mourinho told BT Sport at Old Trafford.

"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."

Banana boost

In a curious scene during the second half against Rostov, Mourinho relayed a banana to Marcos Rojo to give the Argentine centerback an energy boost.

"If you were tired any time in your life, I was tired many times, I know what the body needs," Mourinho said.

"It needs anything. The player asked for a banana. But it's not to laugh at all. It's to respect the players."

Pogba departed in the 47th minute after pulling up as he chased an opponent towards the halfway line, with Marouane Fellaini taking his place.

Juan Mata netted the decisive goal for United, firing home from a Zlatan Ibrahimovic flick.

Russian club Rostov came close to taking the game to extra time, but United goalkeeper Sergio Romero saved from Aleksandr Bukharov and Christian Noboa.

"It's another historic game for us," said Rostov boss Ivan Daniliants, whose side had never previously gone so far in European competition.

"We played against one of the best teams in the world. They were obviously stronger, but we fought until the end. We're thankful to our fans for their support."

Agence France-Presse