Maguire admits that talk about the Dutchman being sacked did filter through to the players.
United finished eighth in the Premier League, but won the FA Cup against Manchester City in May.
“It was tough,” said Maguire, per The Mail.
“Some of the things that came out in the lead-up to the Cup Final were really poor, I felt.
“He handled it brilliantly, to be honest. He just took each day as it comes.
“We didn’t see anything different in the manager, so credit to him for the way he handled it – and all his staff as well – because there was so much uncertainty around the club. They didn’t know what was happening the following year.
“It probably did damage our performances and results throughout the season a little bit. Especially when it happened around that Christmas period when we really did fall off.
“But credit to the manager, the way that he handled it. To have the lead-up in the way that he did and to produce a performance like we did in the Cup Final and turn things around was really impressive.
“I don’t think he needed to (speak to the players about it). I think he handled it right. He just carried on day to day as he has been. Training and then preparing for the game as well as he could. He could have downed tools and maybe just thought his time was over, but he definitely didn’t do that.”