WALTHAM, Mass. – Isaiah Thomas recently signed a multi-year shoe and apparel deal with Nike.

And in less than seven months, he has easily become the most popular Celtics player among fans.

Life is good for the 26-year-old, better than most would have expected considering the 5-foot-9 guard was the last player drafted four years ago – something that Thomas said still irks him to this day.

While he has enjoyed a significant amount of success in the NBA, the struggles, the doubts, the steady stream of critics who didn’t believe he had what it takes to play in the NBA let alone be a standout, it’s the song that’s on a never-ending loop in his head.

And he absolutely loves it.

“Oh no doubt; no doubt,” Thomas told CSNNE.com. “There’s still doubt in whatever it is that I do on the basketball court. That gives me motivation and a chip (on the shoulder).”

There are few days and even fewer games when Thomas doesn’t think about seeing 59 players taken ahead of him in 2011, and the feeling that he was just as good – or better – than most of them.

“That night, was a long, long night for me,” he said. “Being drafted 60th … most 60 picks don’t even get invited to training camp. It definitely still motivates me.”

And with training camp just a few days old, those emotions only get ratcheted up even more so this time of year.

It was in the Sacramento Kings’ training camp in 2011 when Thomas, the 60th and final selection of the 2011 NBA draft, began his journey from being the last player taken to a first-rate talent whose play this season will be vital to Boston getting back into the playoffs.

Thomas is a hit among fans and teammates now, but hasn’t lost his appetite for improvement.

“Coming into the league the way I did, I can’t afford to take anything or anyone for granted,” he said. “What you see from me when I’m on the court is all I have. That’s what I bring whenever I’m on the court; everything I have.”

The new shoe deal and of course the four-year, $27 million deal he signed in 2014 help validate his arrival as a player in this league.

But Thomas’ goals have always been bigger, larger than anyone else’s imagination.

That’s because in Thomas’ world, there are no limits on what he can do on the court.

Which is why he always has a smile when asked about starting versus coming off the bench.

He appeared in 21 games for Boston last season and led the team in scoring with a 19.0 points per game. His play was good enough to where he was runner-up for the league’s Sixth Man of the Year award.

Thomas says he wouldn’t mind bringing home that hardware this season; that is, if he’s not starting which is a goal that he has set for himself – and a goal most NBA players have going into a season.

“If that’s my role I definitely want to be the best sixth man,” he said. “If I’m a starter, I definitely want to be the best starter there is. Whatever my role is, I want to do it at the highest level.”