SAN JOSE – San Jose Sharks defenseman Michael Kesselring is in his sixth full professional season and believes he’s just starting to tap into his full potential.

Part of that has to do with Kesselring’s physical well-being, as the 6-foot-5, 215-pound rearguard is healthy again after dealing with a partially torn quad tendon around his right knee and a high ankle sprain in his one and only season with the Buffalo Sabres. He still dealt with some knee discomfort over the summer.

Another reason is his improved mental state.

As the Sharks get ready to play the Sabres on Tuesday to begin a four-game homestand, Kesselring is in a much better place mentally than he was last season, as the injuries and repeated scratches down the stretch in Western New York took a toll.

“I’ve been thinking about it in the last over the last week, and I can’t even describe how much I just feel like myself again. Like, it’s relieving,” Kesselring told Bay Area News Group. “Obviously, the confidence is starting to come back, and I think, too, the injuries — I’ve never really been hurt like that — and just the mental, ‘Am I OK?’ Last year, I was having trouble with confidence.

“This year I’ve felt so good that I haven’t even thought about it.”

Kesselring played regularly with the Sabres from mid-December to early March. But after the March 6 trade deadline, when the Sabres acquired veteran defenseman Logan Stanley, Kesselring only played in two of the team’s final 17 regular season games and in one of the team’s 13 playoff games – in Boston on May 1 when he had just five shifts and 4:25 in ice time.

Kesselring said his knee still bothered him a bit at the end of last season, but he felt healthy enough to play.

“Once they made the trades, I honestly thought me and Stanley were kind of going to play together. That’s what I thought,” Kesselring said. “Then we played San Jose actually in (Buffalo), and I thought we played pretty well, and then I just didn’t play.”

Buffalo had a pretty crowded blue line, too, with Rasmus Dahlin, Mattias Samuelsson, Bowen Byram and Owen Power eating up a chunk of minutes each game. With Conor Timmins and Stanley in that mix as well, Kesselring had little ice time.

“We just had a lot of guys,” he said. “It sucked because I felt like I grinded all year to feel pretty healthy, and then I thought I was starting to play a little better. Then I was starting to feel better, (but) it kind of was too little, too late.”

After he was acquired by the Sabres from the Utah Mammoth last summer, Kesselring suffered a partially torn quad tendon around his right knee during training camp, causing him to miss the first nine games of the regular season. Kesselring then dealt with a high ankle sprain, which cost him another month.

Looking back, Kesselring believes he returned too soon from the knee and ankle injuries, trying to prove his worth to his new organization after the trade.

“There’s a snowball of events,” Kesselring said. “One injury, barely play, don’t play great, don’t feel great, get hurt again, sit out, letting the team down. I felt like I didn’t mentally handle it very well, and it affected my play a little bit. I wish I had taken another two weeks with my knee, another two weeks with my ankle, to really make sure I was ready.

“I was kind of trying to rush myself back, just because I was like ‘big trade, wanted to prove myself,’ and it ended up hurting me in the end a little bit. So you live, and you learn, and it was obviously a very frustrating year, but I feel like I’m a better person and player now because of it.”

For the season, Kesselring had just two assists in 34 games and averaged a career-low 13:24 in ice time. He’s not blaming the Sabres.

“I think most of it was on me,” he said. “You’ve got to be an adult, and I should have said I was hurting a little bit more than I (let on). I should have mentally handled it better. Then I could feel I was running out of chances.

“But I wish at the end I would have just gotten a little bit of a better look, because towards the end of the year I started to feel better and felt like I was starting to move in the right direction. But I knew what I needed to do, and honestly, I didn’t play well enough. Part of it was me not handling it well enough. Part of it was the injuries. There was not one game I was skating like I have this year.”

Kesselring has played top-four minutes with the Sharks since the start of the season and has averaged a career-high 19:18 in ice time through 12 games.

Kesselring was paired with Darnell Nurse from the start of training camp through Saturday’s game against the Boston Bruins. Kesselring admitted he wasn’t at his best against in Boston, where he fought Mark Kastelic after being hit from behind, or in the previous game against the Ottawa Senators.

If that had happened last season with the Sabres, he would’ve probably been scratched the next game.

As it is, it appears the Sharks will stick with Kesselring and pair him with Sam Dickinson. Nurse will be with Jacob Trouba.

“We saw some growth early, and some things that we really like: the length, the size, and the ability to move pucks,” Sharks coach Ryan Warsofsky said of Kesselring on Monday. “There’s still room for improvement in defending and getting into people, and we’ll continue to work on it. But we love the player, love (his) potential. Really, the sky’s the limit.”

Warsofsky would love to see the right-shot Kesselring, in the first season of a three-year contract, and the left-shot Dickinson develop into a minute-munching pair that can provide offense and be trusted in all situations.

“It’s really exciting,” Kesselring said, looking ahead. “I think I’m just starting to touch the player I can turn into, and I’m having a lot of fun right now. I’m excited.”