Jose told a packed press conference: "Robben is playing tomorrow. It is very important because he is top quality.
"He has been training with us no more than ten days but he started showing his potential over the last few days. The injury was completely gone two or three weeks ago but now the confidence is coming. His fitness condition is okay, he has been working hard and the boy is ready.
"He was injured in the pre-season, has never had one game for Chelsea in England and is full of enthusiasm. For me and for Chelsea it is fantastic because he is one more option, especially now when we have a lot of games.
"I don’t know if I will start with him but he is ready although I don’t believe for 90 minutes."
Arjen broke a bone in his foot during pre season and has suffered several set backs. But Jose is adamant that he is not being rushed back due to our lack of goal scoring at present.
Jose insisted "He is coming back in the right moment. He is not a pure striker but he is an attacking player. He gives me much more options.
"I see him playing outside left, his natural position. I see him playing outside right. I see him playing together with Damien Duff, changing positions. I see him playing in a pure 4-4-2 as a second striker. I see him playing in a 4-3-3 behind the strikers.
"He is a top class player and top class players adapt to different positions and different styles.
"Also the team is happy because the team see in the pre-season the player he was starting to be for us."
Jose also feels that Robben's return could help Batman (Mateja Kezman) discover his scoring touch.
Mourinho said: "We all feel that Kezman can improve a lot with Robben because there is a big connection between them. They know each other well, their movement, and I hope in the next two matches Robben can play both and Kezman can score his first goal. The moment is arriving because the boy is working so hard.
"We felt the connection in the United States when Kezman and Robben were playing together.
"I can remember easily the game against Roma when at half-time I put Kezman and Robben in and in the second-half they killed the game with two goals between them. After that Kezman was sent-off and Dacourt killed Robben and everything was finished. But now Kezman is getting better and better and Robben is ready. I hope that it can bring something extra to us."
And now on to Smertin. Jose said "I gave him [Smertin] a rest against Man City, a physical and mental rest and he played 85 minutes against CSKA. He recovered well and he showed himself in a good condition and he will play."