Chelsea goalkeeper Mark Schwarzer feels the squad does need fine-tuning for next season.
Hopes were high among Chelsea fans when Mourinho returned to Stamford Bridge last summer but it looks as if this year will be the first since 2011 that the club have not won a trophy.
However, Schwarzer told the London Evening Standard: "When you compare this season with last and the fact we're still in the title race with a couple of games to go and reached the Champions League semi-finals, we've definitely made massive progress.
"Obviously, silverware is the aim but you can't say the season has been a disaster. There are people that enjoy it when certain players and managers don't do well. We are very close within the group. We want to do well and improve. The boss has been excellent and I have learned a lot from him.
"I'd agree a few more signings in the summer would help. Chelsea are always looking to improve and want to compete with the very best. To do that you have to invest year in, year out in new talent."
