Once again we brought a hungry player who wants to be successful, who is still 31 and wants to live this experience with us.Aitor Karanka
The 31-year-old penned a two-year deal on Monday after leaving top La Liga side Atletico Bilbao having played there for 11 years.
And despite receiving a host of offers from clubs in Spain and across Europe, he elected to be part of Karanka's project at the St. Andrew's Trillion Trophy Stadium.
“Mikel is the kind of player who everyone knows about him. He has played in Athletic Bilbao, he has played in the Spanish national team, as a young player at Liverpool," said Blues' Head Coach Karanka.
“He is a very good player and person who is going to bring us experience, a very good person.
“I am not going to say I am surprised he came here, but when we started to be in touch I knew it was going to be difficult to sign a player like him
"Once again we brought a hungry player who wants to be successful, who is still 31 and wants to live this experience with us.
"He told me he had offers in Spain, even other countries with more money but he is the profile of player who I love because the first thing he wanted is the project and he knew that we have a nice project here.
"He forgot about staying in his comfort zone or going to those countries with a very good contract, he wanted to come here and join us."
A real bonus for Blues is that San Jose is equally adept in both midfield and defence.
"He can play central defender with four defenders, he can player defender in a line with three defenders, as a defensive midfielder playing with three in the middle of the pitch, he can play with another midfielder just with two in the middle," continued Karanka.
"He can bring us a lot of alternatives – which is good.
"I know him personally, when we were in Bilbao. When he was having his trial in Bilbao, they were my last days there. We were playing against Colorado Rapids and then I went to Colorado Rapids. The day he arrived at the Bilbao academy I was leaving – now we are together 14 years later."
In terms of making his Blues debut, Karanka says it's now just a case of deciding when his fellow countryman is up to speed.
"I can’t tell you (when he will make his first appearance) because I need to check him better but the main thing is we are not going to need him right now because the team is playing well.
"We have one week after this game, then another two weeks to work. So, he is going to have at least three weeks, almost a pre-season, working with us. That’s going to be perfect for everybody.
"If I can use him on Saturday, I will use him for sure and if he is fit for the following Saturday and I think it is going to be good for the team I will use him.
"If I don’t see that he is 100 per cent fit we will wait. In this team there is no one player that we can’t miss."