Having been awarded through a successful arbitration case a raise of $850,000 to $1.3 million for the 2010 season, a beaming Mathis was ready to strap on his gear and get down to business at Tempe Diablo Stadium.
That part of the game never has been at issue for Mathis, whose defense never rests. It's his bat that has raised red flags, and he feels he made a major breakthrough in October when he torched the Red Sox and Yankees staffs, hitting .583 with five doubles in 12 at-bats.
"To take that confidence and that feeling I had the last two weeks, bring it here and be consistent," Mathis said, outlining his game plan. "Pound it into my mind to be more consistent.
"I've been saying all along I've been trying to make adjustments to become more consistent. That's what we're trying to bring into Spring Training. The No. 1 thing is being consistent."
A career .277 hitter in the Minor Leagues with a .444 slugging percentage, Mathis is looking to significantly improve his .200 career average and .320 slugging mark in regular-season play for the Angels. His 20 homers and 99 RBIs in 749 at-bats indicate that he has power potential that has been largely untapped.
Mathis' stunning postseason outburst -- featuring a walk-off double to claim Game 3 of a dramatic American League Championship Series against the Yankees -- clearly elevated his spirits.
He carried that positive frame of mind home to Marianna, Fla., for another winter of preparation, physically and mentally.
"I got a lot of work done in the barn," he said.
When he wasn't slamming baseballs or weights, he was doing homework on the Internet for his arbitration case. Mathis took part in identifying areas of statistical data that apparently weighed in his favor with arbitrators, who rejected the Angels' offer of $700,000 in rendering their decision on Friday.
"There were so many numbers, all kinds of stuff," Mathis said. "Obviously, in my case, being in there on the defensive-side, it really helped."
In terms of his pitchers' earned run averages while he's been behind the plate, probably the single most important number for a catcher, Mathis has been among the AL leaders throughout his budding career.
He described the atmosphere in the room during the 3 1/2-hour session as "nasty." He was represented by agent B.B. Abbott with assistance from Barry Meister and the Major League Baseball Players Association.
It might have been a watershed case, arbitrators showing they're willing to look beyond hard offensive numbers for barometers of value.
"We had an hour to talk, then they had an hour, then each side had a rebuttal," Mathis said. "You can prepare yourself for that stuff. Try to put your hard hat on and go through it.
"I was involved a little bit, and my guy did a good job of keeping me informed."
Mathis is in the familiar role of competing for starts and at-bats with best buddy Mike Napoli, whose power production is his calling card.
Mathis had 78 starts behind the plate in 2009, with Napoli taking the other 84. They graced the lineup together 16 times, going 11-5 with Napoli exploding as a DH.
Manager Mike Scioscia has an abundance of riches behind the plate, with Bobby Wilson, Ryan Budde and premium prospect Hank Conger hoping to play their way into the picture sooner than later.
Scioscia has watched Mathis evolve into a complete catcher, in the top tier defensively, and has been waiting for his offense to catch up. The postseason eruption, Scioscia believes, could have been a springboard to bigger and better things.
"Jeff can do everything you would want a catcher to do," Scioscia said, referring to his defensive skill-set and game-calling abilities. "His confidence is higher from the playoffs, from the way he played on the offensive side.
"Maybe the confidence he gets will be a catalyst as far as what he needs in the batter's box during the season. Jeff has paid a lot of attention to his offense over the years."
As with his defense, Mathis' dedication never has raised questions. How many big leaguers spend their offseasons living in a custom-made barn equipped with a batting cage and state-of-the-art weight room?
Those are Mathis' quarters back home in Marianna, where fellow catcher and Floridian Mike Napoli came calling again this winter.
"We did some hitting and some hunting," Napoli said, grinning. "Had a good time."
They'll room together again this season near Angel Stadium, best buddies sharing a passion for the game and a common desire to help drive the Angels to a World Series title.
They came within two victories of reaching the Fall Classic after a tumultuous ride through the 2009 season, and nothing short of a World Series ring will satisfy them this time around.
"That's what it's all about," Mathis said. "That's what drives us. We want to take it all the way."
Lyle Spencer is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.