"Aaron Cook's jammed right big toe has put the Rockies in a bind.

The injury will force the ace right-hander to miss Tuesday's start against the Pirates. He's penciled in to start Saturday in Florida against the Marlins.

Manager Jim Tracy said this morning that either veteran Josh Fogg or rookie Jhoulys Chacin will replace Cook for Tuesday's game. Tracy's preference is to go with Fogg, but that plan would be scrapped if the Rockies need Fogg for long relief today or Monday vs. the Cubs.

"We are making very good strides with Aaron," Tracy said. "But we feel like if we push it and start him on Tuesday, we running the risk of having this be a toothache that won't go away for a while."

Tracy said the next two games are too important to simply rule out using Fogg and forcing the club to use back-of-the-bullpen starters such as Rafael Betancourt in roles they are not accustomed to.

Fogg, who earned the nickname "The Dragon Slayer" in 2007 when he consistently bested some of the best starters in baseball during the Rockies run to the National League pennant, has been steady out of the bullpen. He's 0-1 with a 1.93 ERA. However, he has not made a big-league start this season and he's pitched just 28 innings in 16 appearances. "