He's starting right where he left off, hitting in the two hole. He has an RBI double so far tonight.
Edit: Oops, here's the blurb from Rotoworld:
Rockies activated infielder Kaz Matsui from the 15-day disabled list.
Matsui will get his starting job back after missing five weeks. The disappointing thing is that he's going right back into the second spot in the lineup, even though Troy Tulowitzki hit .297/.387/.429 there. He scored 17 runs in 23 games. Tulo is batting seventh tonight, leaving him with less fantasy value.