Doesn't he tend to play more forward for Bilbao?
Nah. Good, old fashioned CM. Passes it easy but smartly, works hard, runs all day, good first touch and technique. Last I saw was when Bielsa was there so not sure if he's improved or declined since then.
I've never seen him play, so I'll take your word for it. I've read a few sites that have him as an AM.