The Hammers talisman has not begun a match since January — the month when he had his head turned and saw a lucrative move to Chinese Super League side Shanghai SIPG collapse.
Pellegrini said: “I think he is ready to return to his position.
“Marko was out of the team for several reasons. First because his mind was not right when he had the option to go to China, then he returned but didn't work for one week and needed time to recover. After that he was going to play against Manchester City but was ill.
“The team in that moment was playing well. That is why he started on the bench but he is always involved in the game. So there are lots of reasons why he is on the bench."
The Chilean continued: “He has recovered, is now 100 per cent fit in his mind and physically."