Updated

Buffalo Sabres goaltender Ryan Miller revealed Thursday that the injury that sidelined him late in the regular season was a concussion.

Miller told reporters there were four shots in a one-week span in late March that hit him in the head, with blasts by New Jersey's Brian Rolston on March 26 and by Toronto's Dion Phaneuf on March 29 doing the most damage. However, Miller said it was the cumulative effect of the pucks' impacts that forced him to sit out four games.

Multiple media outlets at the time reported that Miller's injury, which the Sabres listed as an upper-body injury, was a bruised collarbone suffered on the Phaneuf shot. Miller acknowledged Thursday that he did have a significant bruise in the area of his collarbone, but not bad enough to force him to miss as many games as he did.

He returned to play parts of the final two regular-season games, and started the Eastern Conference Quarterfinals against the Philadelphia Flyers in fine form, stopping all 35 shots he faced in a 1-0 shutout victory.

He also had a 1-0 shutout in Game 4, but finished the series allowing nine goals in the final two games, capped by him being pulled less than two minutes into the third period of Game 7. It was the first time Miller had been pulled from a Stanley Cup Playoff game.

For the series, he posted a 2.93 goals-against average and .917 save percentage.

Contact Adam Kimelman at akimelman@nhl.com. Follow him on Twitter: @NHLAdamK