Not much is known about what's ailing Kris Letang, but we do know he won't be traveling with the Pittsburgh Penguins on a five-game road trip that will span the next eight days.

Officially listed as being out with an upper-body injury, Letang hasn't played since Feb. 21, and head coach Mike Sullivan - who recently admitted the timeline is longer than day to day - isn't keen on discussing the particulars.

"Our medical staff has a good handle on it," Sullivan said Tuesday, according to Jason Mackey of the Pittsburgh Post-Gazette. "When he’s ready to play or he’s getting close, and we get him on the ice, we’ll let you guys know. I really don’t want to go down the road of talking details of his injury. We’re hopeful here that he’s making progress."

Letang has missed time in recent years due to a variety of injuries, concussion and stroke being the most serious.

In 41 games this season, he's recorded five goals and 29 assists.