Ruben Amorim says Kobbie Mainoo “needs to fight for his job” and hinted Manchester United might be able to bolster their squad in the January transfer window.
The 20-year-old has been a major talking point this season, with the talented midfielder's wait for a Premier League start ongoing in a campaign that began with his loan request being rejected.
Mainoo looked lively when brought on in Monday's chaotic 4-4 draw against Bournemouth at Old Trafford, where his half-brother Jordan Mainoo-Hames wore an eye-catching 'Free Kobbie Mainoo' t-shirt.
The stunt went viral and Amorim says there is no issue with the England international, only a desire for the player to kick on and prove his worth.
"He's a shy boy, but it's not his responsibility," Amorim said. "He's responsible for his acts and his act was to play well in the last game, so I'm just focused on that.
"I had the situation in Sporting (Lisbon) that my brother wrote something in the internet and I have to answer for that.
"My explanation is, 'He has his life, he has his opinion, it's nothing to do with me', so I will do the same with Kobbie.
"Kobbie needs to fight for his job. I think that it's not a bad thing to be on the bench of Manchester United when you are 20 years old.
"I remember (Cristiano) Ronaldo was on the bench, (Wayne) Rooney was on the bench sometimes. (Juan Sebastian) Veron was not playing.
"I remember all the history of Manchester United and (there is) nobody this didn't fall (to), so let's continue in trying to avoid the nonsense and the noise.
"Believe it or not, I just want to want to help the team to win and help Kobbie to be a better player."
Amorim says Mainoo may start in Sunday's trip to Aston Villa, with United without six first-team players due to a mixture of injury, suspension and Africa Cup of Nations action.
"I don't want to show anything to anyone," Amorim said. "I'm just saying that I'm trying to win games and to show to the players that, if you do things right, you will play no matter what the name."
Amorim revealed he could perhaps switch to a back four rather than keep his preferred three-man system to cope with absentees during the festive period.
With the transfer window opening next month, Bournemouth's Antoine Semenyo, whom the manager last week called a "special player", is among those of interest as United continue their attempts to build for long-term success.
"We'll see," Amorim said when asked if the club had told him there is money for January business.
"The only thing we know is that we only would try to bring players that we think are going to be the future.
"It's not going to be to save something in this moment, to cope with the losses of three players for AFCON. It's not going to be like that.
"I don't know what is going to happen, but it's possible that we can do something."
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