In most situations, the decision to keep Isaiah Thomas would be considered obvious. He is young. He just earned second team All-NBA honors. He didn't just make a leap this past season -- he has habitually taken a leap, every season, at least dating back to the time the Boston Celtics acquired him. He has already proven he can blast into superstardom, take over fourth quarters, and bring his team to the Eastern Conference Finals.

But the Celtics have long stated they only want to win an NBA championship. And so some smart people have wondered: if that is true, should the team trade Thomas, as brilliant as he is?

Before we discuss that question, a few notes:

1. Thomas' current contract, one of the NBA's biggest bargains, expires at the end of next season. Assuming he returns fully healthy after a right hip injury, he will be due a gigantic raise, maybe to the tune of a contract totaling about $200 million.

2. Thomas' story turned inspirational long before he overcame a knocked-out tooth, a lingering hip injury that could require surgery, and the death of his younger sister to lead the Celtics deep into this year's playoffs. He is already the most productive last draft pick ever. He recently finished not just the greatest season ever for a sub-6-footer, but one of the most efficient high-volume offensive seasons ever recorded by a player of any size. Thomas' rise borders on fictional, and he has always pushed himself to improve. The Celtics front office shared its deep appreciation after Thomas' hip knocked him out of the postseason:

Can't say enough about #thelittleguy @Isaiah_Thomas - last month one of the guttiest performances (thru all sorts o' stuff) I've ever seen. — Mike Zarren (@mikezarren) May 20, 2017

Legendary season by @Isaiah_Thomas 💪🏼With the personal tragedy and injuries he's overcome, getting through game 7 was heroic#thelittleguy — Danny Ainge (@danielrainge) May 20, 2017

3. The Celtics could keep Thomas, hold on to the No. 1 pick, recruit Gordon Hayward with their cap space this summer, use another lottery pick from Brooklyn in 2018, and live the next decade or so as at least a good-to-great team. The salary cap dictates they will need to make some roster concessions and/or risk paying hefty tax bills for a long time, but they have enough already to compete (at least for Eastern Conference Finals berths) for a long time.

Though Celtics president of basketball operations Danny Ainge recently tried to squash the talk, Thomas' future became a topic of debate (read the following stories by Tim Bontemps, Tim Cato, and Tom Ziller) because the Celtics aim to win a championship in an era when LeBron James and the Golden State Warriors loom like mountains over the rest of the NBA. To overcome the Cleveland Cavaliers first, then the Warriors, the Celtics will need to capitalize on all their previous good fortune. They have made wise decisions for years, but the string of great front office work has only set up more difficult choices. Without changes, they risk becoming a habitual luxury tax payer that falls short of contender status.

The arguments for exploring Thomas' trade market goes something like this:

1. Short guys may not age well

What if Thomas loses a step as he rounds 30? What if he loses the insane ability to finish over larger guys? What if his hesitation-and-go move becomes slightly less effective, his overwhelming offensive production tails off, and the Celtics are stuck paying three really good but not quite elite players (let's say Thomas, Al Horford and Hayward) max money while James and the Warriors still rule the NBA world?

In short: What if Thomas dips and Celtics ownership is forced to pay oodles of money for a non-contender?

2. Short guys struggle to defend

Even if Thomas ages well, he is a defensive liability in ways that matter more deeper into the postseason. Not every team can damage the Celtics for starting a totally undersized point guard, but the best clubs will target Thomas possession after possession. Sometimes that actually works against the opponent. You might remember Bradley Beal failing on a number of post-up attempts early in the second round, or how so many teams brush aside their usual offenses to isolate a bad player defended by a shorter guy. But other times the Celtics crack under the weight of the pointed attack. Early in Game 7, the Wizards went after Thomas repeatedly for buckets. Simply put, Thomas' height limits what the Celtics defense can accomplish. And it matters more against teams like the Cavaliers and Warriors.

3. The Celtics' cap situation is changing

To this point, the Celtics have maintained cap flexibility while loading up with good, young players. Even after reaching the Eastern Conference Finals, they will be able to clear maximum cap space this summer if they find the right guy willing to sign in Boston. But the affordability of the Celtics' roster is set to change.

Kelly Olynyk's a restricted free agent this summer and could get paid more than you think. In just a year, Thomas, Marcus Smart and Avery Bradley will be due for big contracts. Especially if the Celtics draft Markelle Fultz at No. 1, which seems like the most likely outcome, it won't be wise to pay all of the other guards. And Thomas would be the most expensive of them all.

4. Fultz might be great

You might have heard Fultz, the probable No. 1 draft pick, plays the same position as Thomas. Though it's unlikely two super-skilled guards would flop as a partnership, it's possible they would block each other from reaching their full potential. Fultz might take touches from Thomas, whose defensive limitations would hurt more in a lesser offensive role. Thomas might stunt Fultz's development in one way or another.

If Fultz proves himself quickly as a franchise cornerstone, some folks would argue that would make Thomas -- another playmaker -- at least somewhat expendable.

My counterarguments:

1. There has never been a short guy like Isaiah Thomas

The list of sub-6-footers lasting beyond year 30 is, for lack of a better word, short. Only a handful of guys that size have played well into the fourth decade of their lives. Fewer, even, have done it while shouldering a significant scoring load.

But comparing Thomas to other guys under 6-feet tall seems misguided. The sample size of guys ever to play in the NBA at that height is small. The sample size of guys who have been any good is smaller. And the sample size of guys who have reached Thomas' level is non-existent. According to Basketball-Reference.com, he became the first sub-6-footer since 1959 to qualify for second team All-NBA. Shout out to Slater Martin, the last to do it, but he did so while averaging 9.7 points per game in an eight-team league.

Thomas is an anomaly. He is an impossibility. Maybe he will fall off quickly, as some fear, but the best sub-6-footer ever is playing in an era of longevity. Point to Allen Iverson's early-30s tail-off as a reason for concern, but A) it's safe to assume Iverson didn't pay nearly as much attention to his body as Thomas does, and B) Iverson averaged 33.0 points per game during the season when he crossed the 29,000 career minutes played mark. Thomas has only played 13,124 regular-season minutes; assuming his hip injury doesn't set him back long term (he indicated doctors don't sound concerned) there's reason to hope he has many dynamite seasons left.

2. So?

A lot of point guards get picked on deep in the playoffs. Kyrie Irving isn't any better at defense than Thomas; he just has LeBron James next to him. Likewise, the Cavaliers decimate everybody with the 1-3 pick-and-roll, not just Thomas and the Celtics.

If you're pointing to Games 1-4 of the Eastern Conference Finals as indisputable evidence the Celtics need to move Thomas, you're doing it wrong. His team got blasted with him, yes, but he was limping around on a hip that could require surgery, just days after visiting the hospital for tests. Boston couldn't have played much worse early in the series, Thomas was totally ineffective, and the combination made for an embarrassing Game 2.

But Thomas is so great at offense his defensive limitations -- which are real -- are off-set and then some. Remember that Game 7 against the Wizards I mentioned earlier? After getting picked on in the first half, Thomas finished with 29 points and 12 assists in a game the Celtics doubted he would play; during the second half, he went for 17 points, six assists, zero turnovers, and a +11 rating.

It is true Boston's defense needs to improve, but there are ways to do it with Thomas on the team. Add some more rim protection and rebounding. Get more frontcourt length and physicality. Not everything should be pinned on Thomas, who defends with toughness and intelligence, albeit an obvious lack of size. Though his height is a legitimate issue, he was nowhere close to the city of Cleveland while James and Irving scored 1 billion points apiece during Games 4 and 5.

It's tough to blame Thomas for failing to bring a team that wasn't built to make the Finals, to the Finals. He got the Celtics as far as anyone could have reasonably hoped for them to go.

3. The Celtics' cap situation is changing regardless

Even if the Celtics trade Thomas, Bradley and Smart are going to get paid. As SB Nation's Ziller recently put it:

Moving Isaiah almost forces you to pay Smart and/or Bradley (or another guard) big dollars to ensure Fultz has help. Would you rather pay Isaiah $30-$35 million, Bradley $25-$30 million, or Smart $20 million? You might pick Bradley -- defense and shooting, it's a hard-to-beat combination -- but it's really preference at that point. The bottom line is that none of the three major incumbents is going to be cheap in a year.

It's not like trading Thomas would allow the Celtics to keep chasing other maximum free agents forever and ever. They'll need to make backcourt choices anyway.

If they move Thomas, they would essentially be pivoting toward the future, and beginning to build around Fultz, Jaylen Brown, and the rest of their younger pieces, including the 2018 Nets pick. Maybe that's OK if you think the Cavaliers will be invincible for several years, but remember: that team won't always be this great. James will one day show the downside of age, parts of the supporting cast are already on the back nine of their careers, and Cleveland hasn't left itself much room to hunt upgrades. The Eastern Conference has been dominated by one team for years, but the landscape won't always look like it does now.

4. Fultz becoming a star would be great

Did anybody else see how many bodies the Wizards sent at Thomas? Or how the Cavaliers double-teamed the star on most ball screens? What if another top playmaker (let's call him Markelle) was lurking on the other side of the court to crack through a stretched-out defense?

The Celtics can score plenty already with Thomas, Horford and a bunch of peripheral pieces, but the offense would shoot to another level with another stud playmaker. What's cool about Fultz, from the team's perspective, isn't just that he's a really talented young dude. He's also a tall, lengthy point guard who can shoot; on both ends of the court, his skill set theoretically makes sense next to Thomas'. Helping the odds of the duo thriving, Brad Stevens' offense spreads touches around and Thomas is plenty comfortable working off the ball. Great teams need multiple stars, and clubs with championship aspirations typically choose to keep all-NBA guys.

So what should the Celtics do?

One option: Chase Hayward, draft Fultz, keep Thomas, and continue straddling the line between the present and future. Maybe that core would never be enough to knock off the Cavaliers and challenge the Warriors, but over time Fultz, Brown or the '18 Nets pick could emerge to open a Celtics' window. The relatively inexpensive rookie contracts will allow the Boston front office to groom young stars while paying established ones. The better the team gets, the more likely ownership will be to pay for the nucleus to stick around.

The Boston front office could pivot toward a youth movement later if the current group never takes the next step, but holding onto both building options (present and future) as long as possible makes sense. Imagine how many points the Celtics will score if Thomas is joined by another All-Star playmaker like Hayward. And if Hayward stays in Utah, the plan would still be a good one: keep winning 50-plus games, developing young talent, and looking for an opportunity to break through as a contender.

Maybe one day trading Thomas will look like the right move. But right now he's the Celtics' best player, an offense unto himself, and still two years from 30. Teams pay a lot to hold onto guys like that.