According to the Drillers Pre-Game radio broadcast, Darren Clarke has been called up to Colorado from Double A, the first this type since Tulowitzki last year. I have yet to find confirmation on this online, so I cannot tell you whose spot he has taken on the 25 man roster, but can tell you that Clarke's Double A spot has been taken by Mike DeJean, working back from arm surgery.
I had the privilege of seeing Clarke's last Double A outing Tuesday night, and you can get my extended thoughts in the Wednesday Pebble Report. If you're more of a Cliff Notes person: He's very tall. He throws very hard. His slider breaks a lot. He strikes out a lot of guys. He throws strikes...
Clarke cracked the Rockies' Baseball America Top 30 last year, and was named to the Cal League's version of an All Star game. He's been on the disable list for most of the year, and only has 6.1 innings above High A ball for his career, but he has polished rates for both levels and his stuff should make the jump easier. Hopefully he becomes the third quality youngster in the Rockies' pen quickly.
So again, no official link to confirm this with yet, so please keep checking back with this story to find who the exiled player may be.