BOSTON -- I can pinpoint the exact moment when the Boston Celtics morphed from "plucky" to playoff worthy, from "intriguing" to captivating, from a team that was "fundamentally sound" to one that is creative and convivial and cool to watch.

It was when Isaiah Thomas showed up, pulled on Sherman Douglas' old No. 4 jersey and promptly scored 21 points in 25 minutes and got tossed from the game, all in his action-packed debut.

Sherm would have liked that. He played when Paul Gaston was the Celtics owner and declared at a function, "I think I know our team stinks.'' Upon hearing those comments, the feisty point guard retorted, "Well, I think he stinks too.''

Isaiah Thomas doesn't stink. No other bench player in the NBA has scored 20 or more points in 26 games and few, if any, guards that measure 5-foot-(ahem)-9 inches strut to the free throw line with such notable regularity.

In Sunday afternoon's lopsided win over a gutted Cleveland Cavaliers roster, Isaiah shot six free throws. Nobody shot more. This is becoming a regular occurrence.

Isaiah Thomas has averaged 21.4 points per game in six games in April, in which the Celtics are 5-1. Brian Babineau/NBAE via Getty Images

In fact, in a win over the Detroit Pistons last week, Thomas sashayed into the paint virtually untouched for much of the night and shot as many free throws (10) as the entire Detroit team. Oh, and he scored 34 points. After the game, when asked what went awry, Pistons coach Stan Van Gundy bluntly admitted, "We couldn't contain Isaiah Thomas.'' Usually, free throws are boring, but not the way Thomas accumulates them. He has a knack for lulling his defender into believing he's just dribbling, minding his own business, contemplating the gaudy Big Dig price tag, then -- boom -- he suddenly accelerates to the hole or quickly pulls up and launches a 3-pointer, in either case making certain that he draws contact and gets the whistle. "You know he's going to do it,'' lamented Cavs forward James Jones, "but he gets you anyway.''

Thomas "got" Jones at the 10:18 mark of the second quarter. At the time, it was a tie game, which was a tad disconcerting considering the Celtics began the contest with an opening 9-0 burst. With LeBron James, Kyrie Irving and Kevin Love all in street clothes, there was absolutely no excuse for not winning this basketball game.

By the time it was over, Boston had held Cleveland to 78 points and had won by 39.

"Coach [Stevens] said we were a very mature team tonight for 48 minutes,'' Thomas reported. "That's a good thing.''

Since Boston acquired Thomas, the team is 18-11 and completely and totally zoned in on being a playoff team. Seriously. The little dude has done the impossible -- he's convinced fans who were programmed into a "gotta lose and rebuild" stupor into rooting unabashedly for their team to win, lottery pick be damned.

Thomas has proven to be the ideal antidote for a team that had trouble closing out games because of a lack of a pure scorer. Thomas often plays alongside Marcus Smart and Avery Bradley, who simply can't handle the responsibility of controlling the ball right now. The beauty of it is Thomas needs the ball in his hands to be effective, which is perfectly all right with his backcourt counterparts because when Thomas penetrates and draws two collapsing defenders, he kicks it out and creates open looks for guys like Bradley, Smart and Jonas Jerebko. "It's a lot of fun playing with him,'' Smart said. "His ability to get into the paint and doing some of the things he does out there ... it's fun to watch. He makes the game so much easier for the rest of us.'' After the Celtics finished off the Cavs, they sat back and waited for the results of the Indiana Pacers game with the Oklahoma City Thunder. A loss for Indiana would have clinched a playoff spot for Boston, but alas, that would have to wait for another day.

Asked how much it would mean to him to make the playoffs Thomas answered, "For me personally? It's everything. In my NBA career, I haven't been to the playoffs. It's something I want to experience. I heard it's fun, it's exciting.''

Maybe that's the most meaningful quality that Thomas has imported to the parquet. He's not a veteran who has been there, done that, who only knows winning and finds rebuilding untenable.

Thomas is trying to make his mark now, here, and he has galvanized a young group of players, many of them castoffs, into believing all of this is worth fighting for.

He told the assembled media Sunday that once he heard about the trade that shipped him from Phoenix to Boston, he started focusing on the postseason. "I honestly did,'' Thomas said. "When I came here, Isiah Thomas shot me a text that said, 'They are a game and a half out of the eighth spot,' so I felt like it was realistic. "These guys have been fighting each and every day. We've been fighting and fighting.''

The fight has been embraced by a patient fan base that has long rewarded effort with affection. (See their prolonged and continued love for Kendrick Perkins, which was on display again Sunday afternoon.)

Midway through the second quarter, Thomas pulled them from their seats when he drove left, did the Rajon Rondo peekaboo pullback, drew a crowd of Cavs jerseys, then threw a wraparound pass around 7-footer Timofey Mozgov to Jonas Jerebko for a corner 3-pointer.

No one is saying Thomas is a better passer than Rondo. No one is saying he's a better player, either. But he's the better player for this team. They need someone who believes scrapping for the eighth (or seventh) playoff spot is a noble goal and a significant accomplishment. Remember when Doc Rivers said recently that Brad Stevens was a much better fit for the Celtics at this juncture than he would have been? Same applies here. Rondo had the right to desire a change of scenery. He was an integral part of the 2008 championship, and that's chiseled in stone, but he was no longer interested in the long haul ahead. Who admits they haven't played defense in two years? That one still rattles my brain.

Back to free throws. Since Rondo tore his ACL, he simply hasn't exhibited the confidence to attack the paint like he once did. He has attempted 70 free throws this season and made only 25 of them. That's 35.7 percent.

Thomas has taken 342 free throws this season and made 87.2 percent of them. His 5.3 free throw attempts per game lands him 21st in the league and third among point guards, trailing only the prolific Russell Westbrook (9.7 FTA/game) and former Suns teammate Eric Bledsoe (5.5). Thomas, incidentally, shoots more free throws than any other bench player at any position in the league.

It is a valuable skill, and a critical one come playoff time.

I know what you are thinking. I'm going overboard, and you are right. Thomas is a liability both as a rebounder and a defender because he's so small. That nightmare came to life in living Technicolor in a recent loss to the Milwaukee Bucks when coach Jason Kidd ordered anyone that Thomas was guarding to back him into the paint and post him up. It was shocking how quickly and easily that turned into a successful strategy.

It's a genuine concern, and one of the reasons that Thomas has played for three teams in the past seven months. The other is the idea that he will want a larger role next season, that he will demand to be a starter, which will hamper his overall effectiveness as a game-changer (and pace-changer) and could cramp the development of Smart.

Can we agree to worry about that later? Can we agree Thomas and Brad Stevens deserve the opportunity to experience a taste of the NBA playoffs?

Can we just have fun watching this Celtics team play for something that actually matters.