Antonio Valencia has not played for Man Utd in their last two fixtures and was dropped from the squad for the defeat at West Ham last month.
Jose Mourinho says a 'complicated surgery' has prevented Antonio Valencia from featuring in Manchester United's last two matches.
Valencia, 33, has not played since the goalless draw with Valencia three weeks ago and was widely criticised for 'liking' an Instagram post calling for Mourinho's removal the following morning. Valencia, who was also dropped from the squad at West Ham last month, apologised for the social media snafu and also confirmed he would not play against Newcastle on the morning of that game three days later.
The Ecuadorian did not travel to London for the 2-2 Premier League draw with Chelsea on Saturday but was involved in United's open training session ahead of the Champions League group stage game with Juventus at Old Trafford on Tuesday.
Ashley Young has started at right-back and skippered United in their last two games and could keep his place, although Valencia is available.
"The reason was that he was 10 days without training with a problem," Mourinho said at his pre-match press conference. "Not an injury but a problem that he had a very complicated surgery on his mouth. And 10 days without training needed a little bit of time to recover some level after that.
"I don't like this press conference," Mourinho added following a question about Paul Pogba. "I don't want to speak about Pogba, I don't want to speak about individuals, I don't want to speak to the Spanish journalists because they are only interested in Real Madrid and Ronaldo.
"I am going to play against one of the biggest clubs in the world, one of the biggest candidates of winning the competition, that's what motivates me, that's what bring me here, and I think the press conference is going in other directions. So if it's going in other directions I also want to go in another direction.