Trevor Donovan is going from numbers to letters.

The actor, who has been featured on 90210 this season with a significant gay storyline, will guest star on an episode of CSI in early 2011.

Expected to air in January, the installment will be titled "Man Up" and will feature the unit investigating the murder of a prostitute.

Enter Donovan's character, a casino employee described by CBS as "a handsome beefcake with a great body." Seems about right, no?

This individual will confess to Nick that he was attacked in a bathroom, with the assailant making off with vital aspects of his costume: a sword, breastplate and helmet.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.