The veteran catcher spent seven seasons in Anaheim, and until an offseason deal to the Blue Jays, it was the only professional team he had ever known.
Those past memories created somewhat of an eerie feeling for Mathis when he arrived at Angel Stadium on Thursday afternoon.
"It was a little weird coming back, going into the other clubhouse," said Mathis, who is hitting .294 in seven games this season. "But it was good to see the guys. Good to be here."
The Blue Jays landed late Wednesday night, and Mathis couldn't help but check the score of the Angels game upon arrival. It was then that Mathis noticed former teammate Jered Weaver had a no-hitter through six innings.
When Toronto arrived at its team hotel, the game was in the eighth, which allowed Mathis just enough time to watch Weaver record the 10th no-hitter in Angels history.
"That was pretty fun to watch," Mathis said. "It looked like him and Chris [Iannetta] were on the same page and anytime you put up that many zeroes and then you put up a zero in the hit column too, that's pretty special.
"I saw when I landed, I pulled it up on the Internet, and it was like the sixth inning, and I saw he got through that and I was like, 'Oh, dang.' Then when we drove from LAX ... so I went upstairs and came back down to see it."
Mathis has received just 17 at-bats this season as a backup to starter J.P. Arencibia, but he has two home runs and two doubles with five RBIs during that limited action.