Every weekday from now until September 7, we'll take a look at each player at the Celtics roster: Their strengths and their weaknesses, their ceiling and their floor. We start today with Isaiah Thomas. For a look at the other profiles, click here. 

BOSTON -- Isaiah Thomas is one of the few professional players that everyone seems to love. Maybe it’s the fact that, at 5-foot-9, he resembles the masses who follow basketball. Then again, it could be because his journey is unlike anything we’ve seen in the modern-day NBA. 
Five years ago he was the last player selected in the 2011 draft, a distinction he reflects upon from time to time as a reminder of not only how far he has come, but also of how little teams thought of his game and its ability to translate at the highest level. 
You'll hear a number of executives talk of how they loved him at the University of Washington, and yet only one team -- the Sacramento Kings -- thought enough of him to draft him. And that was at the very end of the night. 
Celtics president of basketball operations Danny Ainge has remarked in the past that he, too, liked Thomas coming out of college. Yet it was Purdue guard E’Twaun Moore -- not Thomas -- that Boston selected with the 55th overall pick. 
Thomas holds no ill will towards Ainge or any of the executives who passed him by. In fact, there’s a part of him that’s thankful.
If he hadn't been selected so late in the draft, there’s no telling if he would have played with the ginormous chip on his shoulder that has not only helped fuel his own personal success, but also proved instrumental in Boston being on the fast track from a team rebuilding into one that’s now poised to compete for one of the top spots in the East. 
Having already exceeded the expectations many had for him, Thomas is an integral part in the building of what the Celtics believe will be a championship-caliber team.


But how much room does Thomas have to grow?

And what’s a realistic floor for Thomas anyway?
I’ll explore those two questions as they relate to Thomas and the rest of the current Celtics roster in the coming weeks as we inch closer towards the start of training camp. 
THE CEILING FOR THOMAS -- Top-5 finish in league MVP voting
Every year there’s a guard who embarks on an exceptional season in which they set career marks in several categories and their team ranks among the game’s best. Boston has the potential to be that kind of club this year, with Thomas being a key catalyst in making that happen. 

He had an amazing season last year, averaging career-highs in scoring (22.2 points) and rebounds (3.0) to go with 6.2 assists.   
But for the Celtics to take that next step and get past the first round, they’ll need him to be even better. And while an uptick in Boston’s success will likely be attributed to the addition of Al Horford, it’ll most likely because Thomas becomes an even more impactful player.
It will require him to step his game up in at least one key, tangible area. That probably would be assists. 
Thomas isn’t likely to significantly improve his scoring because of the improved talent around him, and he doesn’t shoot the ball from the perimeter well enough to be a 40-plus-percent percent shooter on 3s. 
But with the increased talent around him, there is the potential for him to significantly increase his assists numbers. He is a career 5.0 assists-per-game player who has never averaged more than 6.3 in a single season. 
Significantly improving in that area could be enough to land him one of those coveted top-5 spots in the league MVP voting.  
In the last five seasons, the top-five vote-getters usually included at least one emerging guard of note. 
Houston’s James Harden was runner-up to Golden State’s Stephen Curry in the 2015 league MVP race after the Rockets finished with the third-best record in the NBA, with 56 wins. That certainly played a huge role, as did the fact that in 2014 Harden put up big scoring numbers to finish fifth in the league MVP chase. 
Russell Westbrook has finished fourth in MVP voting each of the last two seasons while putting up video-game-like numbers in terms of triple-doubles. And if you go back a couple years, you’ll note that Chris Paul was in the thick of things in 2012 and 2013 when LeBron James won back-to-back league MVP awards. In those two seasons Paul established himself as the league’s best point guard while finishing those years third and fourth, respectively, in the MVP chase.
Thomas could also benefit from continuing to improve as a defender. While he doesn’t play at an All-NBA level defensively, there’s no mistaking the progress he has made in this part of his game. In fact, his defensive rating (points allowed per 100 possessions) has improved every year he's been in the league.
Trending in that direction defensively (his defensive rating was 107.6 as a rookie, and was at 102.6 this past season), along with what we already know he can do in terms of scoring, bodes well for his continue growth as a player and the potential to be a league MVP candidate.


THE FLOOR FOR THOMAS -- Third-leading scorer on the Celtics
We all know Thomas can score, but the way Boston’s roster is constructed now may result in a dip in his usual point production. 
The addition of Gerald Green and rookie draft pick Jaylen Brown provides Boston with a pair of additional slashers to the basket, which will likely result in fewer drives to the rim for Thomas. 
And the domino effect of that would be fewer free-throw attempts for Thomas who is a career 86.3 percent free throw shooter. Last season he averaged a career-high 6.6 free-throw attempts per game.
One possibility for Thomas would be to shoot more mid-range jumpers, something he didn’t do much of last season. 
According to NBA.com/stats, about 15 percent of Thomas’ shot attempts were mid-range jumpers. And when he shot mid-range jumpers, he connected on just 36.5 percent of them. 
Thomas, 27, is smart enough player to know if he has fewer shots at attacking the rim, he must look to become an even better passer. Don’t be surprised to see his scoring dip while his assists numbers take a noticeable leap forward. 
The addition of Al Horford, coupled with the continued development of Avery Bradley, Jae Crowder, Marcus Smart and Kelly Olynyk as viable scoring options, will likely put a dent of sorts in Thomas’ scoring. But if that means more assists and more wins for Boston, Thomas is more than willing to foot that bill.