Van Gaal departed Man United following a disappointing fifth-placed finish in the Premier League during the 2015/16 campaign, although he did win the FA Cup.
The Dutchman has been replaced by Jose Mourinho and Herrera admitted that the players were aware of the speculation surrounding both managers as the season drew to a close.
“It wasn’t a comfortable time, but we are professionals, and so we didn’t allow it to distract us,” Herrera said.
“I must say that the coach remained strong throughout. He never showed signs of surrender and, in the end, we won the FA Cup. Van Gaal is an honest guy and has always put Manchester United above all else.
“In many ways I think he has done a good job.
“I’m grateful to him because he signed me and so gave me the opportunity to play more than 70 games, in two years, at arguably the world’s largest club.”
Herrera garnered something of a cult following at United as he put in a number of top performances under van Gaal only for the veteran boss to cast him aside the next week, more often than not.
However, Herrera’s performances dropped off drastically towards the end of the campaign and he could have no qualms about being left out of the side.
Mourinho’s arrival should signal a chance for players like Herrera to ‘start over’ and focus on impressing the new boss in order to solidify a place in the team.