PITTSBURGH — John Jaso gave himself a Christmas present Dec. 23 of last year.

A first baseman’s glove — and a reason to wear one.

That’s the day the veteran American League catcher signed with the Pittsburgh Pirates to essentially begin a new career as a first baseman.

“He’s embraced the challenge and he’s worked hard at it,” Pirate manager Clint Hurdle said.

Jaso, 32, spent six full major league seasons as a catcher/designated hitter with Tampa Bay, Seattle and Oakland in the American League. He hit .286 in 185 at bats for Tampa Bay last season.

But his days of crouching behind the plate were ending.

“Too many concussions back there,” Jaso said. “In terms of my health, I couldn’t play the position anymore.”

Problem was, he still wanted to play the field.

“I’m just not ready to be a DH all of the time,” Jaso admitted. “The Pirates offered me an opportunity. This is a good team, a good organization, so I went for it.”

He went for it despite playing just two games in the major leagues at first base before signing with Pittsburgh. Opening Day this season marked the first big league game Jaso ever started at first base.

And the first pitch of the game resulted in a hard grounder hit right at him by Matt Carpenter.

“I think that helped John,” Hurdle said in recalling the play. “It got him into things right away without any time to think about it.”

Jaso agreed.

“Instincts just take over,” he said. “I learned a lot about this position in spring training. I got adjusted to the different throws from all of the infielders and how to position myself for certain plays.

“I’m not going over things in my mind while I’m out there and that’s good. I’ve been taking a lot of ground balls in practice every day. I feel a lot more comfortable now.

“Repetition is everything in this game. First base is beginning to feel more natural to me,” Jaso added.

Hitting leadoff in the batting order has always been natural to Jaso, though he’s stolen just 15 bases in his big league career.

When Jaso led off for the Pirates on Sunday, he became only the fifth first baseman to lead off on Opening Day for the Pirates since 1900. The others are Gary Redus in 1991, Rich Smith in 1953, George Grantham in 1927 and Wheeler Johnston in 1916.

“Yeah, you don’t see many first basemen hitting first,” Jaso admitted. “But even fewer catchers hit leadoff and I did that for a while. I’ve hit first in the lineup most of my career.”

Jaso hit leadoff as a DH for Tampa Bay on Opening Day last year — becoming the first DH to lead off an opener since Frank Catalanotto did so for Texas in 2002.

Jaso has been a popular leadoff batter because of his high on-base percentage. That figure stood at .380 last season and is at .361 for Jaso’s career.

By comparison, Starling Marte has a .340 career on-base percentage, Josh Harrison is at .318, Gregory Polanco .316 and Jordy Mercer .308.

“I know how to get on base,” Jaso said. “If I can get on with the guys in this lineup coming up behind me, we can make some things happen.”