John-Michael Liles is out indefinitely with a concussion suffered after he crashed face-first into the boards in Sunday’s win over the Tampa Bay Lightning.

Liles lasted just a handful of shifts in Sunday’s win before tripping over Ben Bishop’s stick in the crease and smashing face-first into the boards while also possibly taking a knee to the head prior to the loud end board collision. Liles was down for long moments, and then had to be helped wobbly-legged back to the Bruins dressing room for initial medical treatment.

The 36-year-old defenseman has a bit of a history with concussions having had at least a couple of them in his 13-year career, including one that forced him out of action for more than a month during the 2011-12 season. Liles had appeared in all 22 games for the Bruins prior to missing Tuesday night’s game vs. the Flyers, and had posted five assists while averaging more than 16 minutes of ice time per game. The 5-foot-10, 185-pound Liles now joins Zdeno Chara as the two eldest D-men now on the shelf with injuries for the Black and Gold, a situation that’s going to test Boston’s admittedly skimpy depth on the back end.

The Bruins didn’t call up a D-man from the AHL for the one-game trip to Philly, and it remains to be seen how much long the 39-year-old Chara is going to miss with his lower body injury.