The Spanish midfielder has been the Blues' Player of the Year for the past two seasons, but has not been an automatic starter under new boss Jose Mourinho, who said that the 25-year-old must adapt his game to work his way back in.
Mata had started three games in a row before being an unused substitute for the third time this season in the midweek win over Schalke 04.
"It did surprise me when he was dropped and I don't think I was the only one," the Daily Mail quotes Silva as saying.
"The years he has spent playing at Chelsea, he has brought a lot to the side and contributed hugely to their team effort.
"Now he's back among the ranks, he is starting to prove what he can do and is producing again. He is a top player and I think he has given Chelsea a lot in his time."
The former Valencia colleagues go head-to-head at Stamford Bridge this afternoon.