Not just in years past, but the present and probably the future, too. And every time anyone questions the veteran's abilities, he usually proves them wrong. When he is faced with adversity, he normally brushes it aside as if he's making a blocker save.
The 36-year-old should be a lock for the Vezina Trophy as the NHL's top goaltender after posting a 35-11-9 record and leading the league in both save percentage (.938) and goal-against average (2.00).
It would be Thomas' second Vezina; he won the award for the 2008-09 season. But as much as he deserves those accolades, he wants something more significant -- to bring the Stanley Cup back to Boston for the first time since 1972.
After completing the regular season on Sunday, Bruins coach Claude Julien gave the players Monday off. The team was back on the practice ice on Tuesday at Ristuccia Arena in preparation for its Eastern Conference quarterfinal matchup against the Montreal Canadiens.
Thomas will be the Bruins' starting goaltender, and if he can play the way he did during the regular season, Boston should be in good shape for a lengthy run toward the Cup. He's also experienced enough now to know he doesn't have to play any differently in the playoffs, he only has to maintain his soundly built consistency.
"Hopefully I don't have to raise my level," Thomas said. "I've just got to keep playing the way that I have."
A year ago at this time, Thomas found himself on the outside looking in. He struggled in 2010 and dealt with a hip injury that did not allow him to perform at the highest level. Fortunately for the Bruins, then-rookie Tuukka Rask emerged as Boston's top goalie and helped them advance to the Eastern Conference semifinals before losing to the Philadelphia Flyers in a historic meltdown.
Thomas had offseason surgery to repair a torn labrum in his hip, arrived at camp healthy and eventually won the starting job between the pipes. If Thomas did not perform the way he did this season, the Bruins would not be the No. 3 seed in the East.
When asked to describe how different it is for him now as compared to last year at this time, Thomas didn't bite.
"I won't even try," he said.
In the past, Thomas has always used the naysayers as motivation, but things changed this season. The only person he wanted to prove anything to was himself. At the start of the season, Thomas didn't dream about the Stanley Cup. He didn't clear a space in his trophy case for the Vezina. He took a deep breath and played one game at a time.
"My motivation was to get back to a level I felt comfortable with to prove to myself I could still play at a very elite level," he said. "If I had thought it through, getting an opportunity again to play in the playoffs would have been on my list, but it wasn't my focus at the time."
It is now.
"It's great to see," said Rask, who will serve as Thomas' backup. "Everybody knows he's a competitive guy and he really wanted to show what it's all about and what he's all about. He made a statement and there's no questions asked about his game anymore."
Julien has said time and again this season that he has confidence in both goaltenders. Julien agrees that Thomas doesn't need to change anything for the playoffs.
"Trying to do too much isn't going to help him," Julien said. "When you've been the best goalie in the league, why would you ask him to do more? It's important for him to understand that. All he has to do is play the way he's played all year, and if he does that he's going to be a good goaltender for us, and he'll certainly give us a chance to win.
"We know what Timmy is capable of doing. What he did for us this year, he did for us a couple of years ago. Arguably, people are going to say he's even better. My point is, he's been one of the best goaltenders in the league and that continued to happen this year."
In four starts against the Canadiens this season, Thomas was 2-1-1 with a .907 save percentage and a 3.21 GAA. In 29 career regular-season games against Montreal, Thomas is 10-14-4/.906/3.04.
Thomas will need to rely on his experience against the Habs in order to be successful, especially playing Games 3 and 4 (and if needed Game 6) at the Bell Centre in Montreal.
"I think that will help," Thomas said. "We can focus in the right place, as far as getting the job done on the ice, rather than getting caught up because it is a very energetic atmosphere. It's very loud and the Bell Centre is a unique arena, and it makes it very fun to play hockey. I think past experiences will help us."
If Thomas continues to exceed expectations and is able to catch fire at the start of the playoffs, there's a good possibility the Bruins will ride him to the finals. It's happened before in the NHL, and the Bruins are hoping it happens again.
"If you get a hot goaltender, it obviously gives you confidence," veteran Mark Recchi said. "You don't want that question mark going in, but at the same time, you have to play well in front of him."
Thomas' counterpart will be the Canadiens' Carey Price, who finished the regular season with an impressive 38-28-6 record in an astonishing 72 games (70 starts). Price was 4-2-0 in six games against the Bruins, and is 13-4-2 in 19 career regular-season games against Boston.
Both Thomas and Price have showed character in rebounding from some adversity a season ago. Thomas set an NHL record for save percentage and posted nine shutouts. Price, who was also on the bench during the Habs' playoff run last season, had eight shutouts this season.
"I empathize with what he has gone through," Thomas said.
Now both Thomas and Price have led their teams to the Stanley Cup playoffs.
Boston's goalie won't feel so bad for his counterpart once the puck drops in Game 1 on Thursday at the Garden. The two netminders don't figure to drop the gloves, as they did in February, but expect to showcase their skills at the highest level possible.
"It's a great matchup," Recchi said. "Timmy's had a great career, and chances are he's going to win another Vezina. I would like to see him take it a little further now."
Joe McDonald covers the Bruins for ESPNBoston.com.