Many, many times. After allowing Joba to throw two inning in what was essentially garbage time, Joe Girardi told Kim Jones, "the process has started." The process through which Joba Chamberlain will be converted from reliever to starter.

From Bryan Hoch:

Chamberlain will still continue to see duty in the late innings, but now it may come at different times. For example, when his pitch count bumps to 50, he could pitch innings six through eight; right now, he could pitch the seventh and eighth or, as he did Wednesday, the eighth and ninth. ...

Though the club has not ruled out a Minor League assignment at some point, Chamberlain said he'd like to feel his way out in the big leagues.

I like it. We had been reading reports for a while now, suggesting that Joba would need an extended trip to the minors to make the conversion. But, him making it at the Major League level is better. After all, 2-5 innings of a converting Joba is better than 2-5 innings from most of our other pitchers.