Character actor Leland Orser is set to don scrubs as a new "ER" doc, while "Single Guy" star Jonathan Silverman is joining a Showtime comedy pilot.

Orser, one of television's more reliable guest stars, will join NBC's "ER" as a trauma surgeon who becomes the hospital's new chief of surgery. According to The Hollywood Reporter, Orser's part will be recurring.

Recognizable from somewhat deranged big screen roles in films like "Very Bad Things" and "Seven," Orser's lengthy list of television credits includes "Law & Order: Special Victims Unit," "Star Trek: Enterprise," "NYPD Blue," and multiple appearances on "Married... With Children."

Orser co-starred in the NBC pilot "Homeland Security," which aired as a two-hour movie earlier this year.

Over on Showtime, Silverman is set to join Eddie Griffin in "Pryor Offenses," based on the comic stylings of Richard Pryor. Silverman will play the agent to Griffin's fast-living young comic.

Best known for partying with a corpse in "Weekend at Bernie's" and partying with Ernest Borgnine in "The Single Guy," Silverman co-starred in ABC's David E. Kelley pilot "The DeMarco Affairs" this past development season. He also appeared in the Showtime movie "Deacons for Defense" last year.