Concussions, especially severe ones, can change people. Robin Lehner dealt with headaches and inactivity for more than three months this spring, so his concussion certainly can be categorized as severe.
The Sabres' new goaltender isn't worried, though. He anticipates being the same guy when he returns to the ice - and that guy is fiery.
The 6-foot-5, 225-pounder is an intimidating presence in the crease. Few forwards are going to test the blue paint with Lehner standing there, no matter his concussion history.
"I'm a big guy, and they can go into me as much as they want," Lehner said this week.
Buffalo hasn't had a goalie with Lehner's temperament since Steve Shields was throwing punches at Garth Snow during the 1997 playoffs. Lehner has landed huge overhand rights during a brawl in the minors. He dropped New York Islanders goalie Kevin Poulin with a shoulder as they were skating to the dressing rooms for intermission. He named his pet piranhas after hockey writers in Ottawa. He snapped his stick over his leg and tossed it down the hall after a loss in February.
"He's high-end competitive," Sabres General Manager Tim Murray said. "It's hurt him a little bit in the past. He's been hard on himself, but he's high-end competitive."
The 23-year-old's spirit is unquestioned. What remains to be seen is if he can stop the puck and become the No. 1 goalie that Buffalo hopes he can be.
"You have to dig deep into this kid's background," Murray said. "You have to dig deep into what a starting goalie is in the National Hockey League. We've done our homework."
The background check was easier for Murray because he's been around Lehner for most of his career. Murray helped draft the goalie for Ottawa during the second round in 2009. He watched Lehner lead the Senators' minor-league team to a championship in 2011.
They've spent so much time together than Lehner is comfortable needling his GM's no-nonsense personality.
"He's been the very nice smiling face," Lehner said during a conference call from his native Sweden. "No, he's a very serious guy to handle with, but he shows a lot of respect and I have a lot of respect for him."
Murray dealt the No. 21 overall pick in last week's NHL Draft for Lehner and forward David Legwand. Lehner is the key to the deal. He needs to plug the gaping hole in Buffalo's goaltending situation.
Despite just 86 games spread over five NHL seasons, Lehner is confident he can step into the Sabres' crease on a nightly basis.
"I'm looking forward to the opportunity," he said, "but I've got to deserve it and I've got to perform."
Lehner's career numbers are average, with a 30-36-13 record and .914 save percentage. His best NHL season was lockout-shortened 2012-13, when he went 5-3-4 with a .936 save percentage. He also appeared in two playoff games that year, stopping 23 of 25 shots in relief of Craig Anderson.
Lehner has served as Anderson's backup for his entire career.
"I just go back and look at almost every single situation where there were two No. 1s, it never works," Murray said. "There was always an unhappy player. It filters through your team.
"Robin needed a change of scenery."
Despite his aggressive personality, Lehner says he's at his best when he's calm in the crease. He's cut down on unnecessary movements. He was essentially sitting still when the concussion happened Feb. 16.
Ottawa teammate Clarke MacArthur was skating hard on the backcheck in an attempt to stop a scoring chance, and the former Sabres forward slid hard into the crease. MacArthur caught Lehner squarely on the chin during the pileup, and both suffered concussions.
"Just because it was a clear shot to my chin, it got a little worse than it should have gotten," Lehner said. "I sat around not doing anything at all for three, four months. That's the first time in my life I've been gone and not moving for that long.
"I'm doing everything I can now to get back into shape. It's two and half months till go time, and I'm going to make it count."
He's eager to make his first shot at being a starter count, too.
"I have a lot to prove," Lehner said. "I like the challenge."