The Spanish striker earned a £50million switch from Liverpool in January 2011 but at Stamford Bridge he has struggled to replicate the form from his earlier career.
Torres has been linked with a move away from the club this summer but has made it clear that he remains committed to seeing out his contract and wants to impress Mourinho.
But the Portuguese boss says his record at Chelsea is only mediocre and is convinced that owner Roman Abramovich will let him rule on whether the player stays.
Mourinho insists that Abramovich has never interfered in his managerial business and did not force him to buy Andriy Shevchenko during his first spell at the club.
"Torres so far is so-so," said Mourinho. "Somebody could expect more because of his potential, because of what he did before. But not so bad as people sometimes try to say.
"There is a balance. Normally, the tendency is to say it was a big mistake. It was a big mistake because it didn't work.
"Shevchenko? It's not true the owner forced him on me.
"Never, never during my time did the owner interfere in the basic things of the manager - training sessions, team selection, the profile of player I want to bring."
Mourinho added: "Do you want to know the truth about Shevchenko? I hope the board is not upset with me. We wanted to buy Samuel Eto'o, he was our target. We wanted Eto'o and the owner was more than ready to do everything to bring Eto'o here.
"He was the player I wanted. Why? Because Eto'o was the only player I could play with Didier Drogba, changing the system for two strikers.
"But he was also ready to play with Drogba with the system we had at the time, with three attacking players with Eto'o coming from the sides. I did the same with him at Inter Milan. We wanted Eto'o and the boss did everything to bring Eto'o and Peter Kenyon did everything.
"In the end, Barcelona said, 'We don't sell, forget it, forget it. Not any price'. The owner did everything to get him, but it was not possible.
"After that, we went to other options and got to Shevchenko. I was happy with him."