Herrera suffered a disappointing 2015/16 season under Louis van Gaal as he was in and out of the side under the Dutchman.
But the Spaniard will be one of a number of players at Man United hoping for a new lease of life under Mourinho. Herrera discussed the appointment of Mourinho in a recent interview.
“Working with Mourinho is a unique opportunity to work with one of the best in the world,” he said.
“He has a widely acclaimed method of working and I want to learn and improve. I consider his arrival to be a one-off opportunity for me to continue to develop and grow.”
Van Gaal used Herrera largely as either a defensive midfielder or No.10 last season and there was a sense that both positions didn’t cater to his strengths. Instead, Herrera seems to thrive when handed a box-to-box role.
Herrera has something of a cult following among United fans and the hope is that Mourinho is able to find a way to get the best out of him in his side next season.