Taylor is out of contract in the summer and has been linked with West Brom, Middlesbrough and Crystal Palace.
The 23-year-old pulled out of the 1-1 draw with Wigan as Leeds failed to reach the Championship play-offs.
"I'm hugely disappointed with Charlie. I think he's been terribly advised all season," Monk told BBC Radio Leeds.
Taylor has been with Leeds since the age of nine and has made 104 first-team appearances since his debut in August 2011.
However, he told the club last summer he did not want to open talks on a new deal and then had a transfer request rejected.
Monk suggested Taylor's head had been turned by the interest reportedly shown in him from Premier League clubs.
"I understand he's very young, and we've tried to help him and guide him from within, but it's very difficult to get him fully committed," he said.
"Had he had some better advice from the outside, I think we would have seen a better Charlie Taylor this season and left on better terms, if that's what's going to happen. But that's over to the club and the player now.
"The club's stance on it is very strong. Hopefully he learns from the mistake he's made."
Leeds United manager Garry Monk has blamed Charlie Taylor's withdrawal from the squad at Wigan on Sunday on the defender's advisors.