NBA championship contention usually isn’t the result of one offseason; rather, it comes from years of incremental progress. That can make for tough sledding and scant optimism during the early stages of roster building.

Near the end, though, excitement roars like a thousand Kevin Garnetts. Once a puzzle is close enough to completion to envision the final picture, it’s hard not to be enthused about bringing everything together.

That’s how the five teams listed here should feel. Each is headed in the right direction, thanks to savvy front-office work and prospect maturation. These clubs have franchise pillars in place to anchor the foundation, plus complementary pieces to support the final construction.

But all are missing the key cogs who can shape their full identity and skyrocket their potential. The right transaction could take each of these clubs from fighting for a playoff spot to comfortably securing one and challenging for home-court advantage or, in some cases, even contending for a championship.

Boston Celtics

hi-res-14cd9ccd6fe06fb018bf9788e747bb0c_crop_north

The Boston Celtics haven’t officially joined the contenders’ table, but their seat is already reserved.

During Brad Stevens’ first three years at the helm, the organization’s win total has rocketed from 25 to 40 to last season’s 48. And the Shamrocks haven’t hit their ceiling yet. So many key contributors are still climbing toward their peak, and everyone on the roster will benefit from two-way big man Al Horford’s arrival.

“Horford has three-point range, passes better than most bigs, doesn’t need the ball in his hands to make an impact and polices the paint,” Bleacher Report’s Dan Favale wrote. “He is equal parts superstar and complement, which makes him a frontcourt unicorn.”

Horford strengthens the backbone of what was already a top-five defense. With the scoring load balanced among him, Isaiah Thomas, Avery Bradley and Jae Crowder, the Celtics should employ a potent equal-opportunity attack. And that’s before even knowing how Boston’s horde of young prospects will help shape the club’s overall identity.

The Celtics are poised for yet another step forward—but only a trade would produce the monumental leap needed to join the NBA’s elite. Between Boston’s young players and coveted draft assets, the trade bullets are locked and loaded should a superstar hit the open market.

Boston has a championship-caliber defense, a coaching wunderkind and a pair of All-Star reserves. But one more star is needed to take this team over the top. If the Celtics can shake that player loose, they’ll enjoy all the perks of full-fledged contender status.

Ideal Player: Blake Griffin

Realistic Player: Gordon Hayward

Memphis Grizzlies

hi-res-d423feba8d37f060045d59b233c7d307_crop_north

The Memphis Grizzlies had a historically active 2015-16 season, suiting up an NBA-record 28 players over the campaign. They were almost as busy this summer, albeit for much more enjoyable reasons.

First came new head coach David Fizdale, a highly regarded assistant who has since assembled an experienced, well-rounded staff. Then, the rookie reinforcements arrived on draft night—Wade Baldwin with the 17th selection, Deyonta Davis at No. 31 (acquired from Boston). Memphis finally spent a mini-fortune on veterans Mike Conley and Chandler Parsons, who signed for a combined nine years and $247 million.

If the Grizzlies stay healthy, they’ll be in the running for a top-four seed out West. Even amid the injuries, Memphis had a top-half efficiency rating when Conley and Marc Gasol shared the floor (plus-1.5, would have ranked 13th). And that was without Parsons’ versatility, Fizdale’s vision, Baldwin’s perimeter shooting and Davis’ athleticism.

As CBS Sports’ Matt Moore noted, a potentially disastrous offseason for Memphis was instead a wildly productive one:

The Grizzlies landed a big upgrade at a position of need that takes care of one of their major problems—shooting and playmaking on the wing. They also kept their franchise point guard who has been a leader on and off the court. … Memphis has staved off NBA mortality and retained its place in the Western Conference playoff hierarchy.

Pushing forward, though, requires even more activity. If the Grizzlies hope to be a conference power and not just a thorn in the sides of the top teams in the West, they need to find one more modernized piece. Whether that’s a floor-spacing big or a three-and-D wing, it has to be a player who impacts both ends of the floor and gives this new-look offense even more room to work with.

Ideal Player: Khris Middleton

Realistic Player: Wilson Chandler

Minnesota Timberwolves

hi-res-528b4da1c2e672440611e461810306a5_crop_north

Does any NBA team have a brighter future than the Minnesota Timberwolves? They employ each of the past two Rookie of the Year winners (Andrew Wiggins and Karl-Anthony Towns), a two-headed monster at point guard (Ricky Rubio and Kris Dunn), a three-point shooting Slam Dunk Contest champion (Zach LaVine), a blossoming big man (Gorgui Dieng) and an ignitable scoring swingman (Shabazz Muhammad).

Only one of those players is older than 25—the 26-year-old Dieng. Arguably the four most important ones are all under the age of 23—Dunn (22), Wiggins (21), LaVine (21) and Towns (20). Oh, and for the first time in their NBA careers, they’re all about to serve under former Coach of the Year Tom Thibodeau.

Depending on one’s perspective, the Wolves are either wildly exciting or altogether terrifying.

“We have a great coaching staff, we have a great organization behind us, but the fact of the matter that we continue to get better is extremely exciting,” Towns told CBS Sports Radio. “Not many teams get to say that, that they continue to get better instead of deteriorating. Everything is looking very much up.”

Minnesota could snap its 12-year playoff drought next season. If Thibodeau solves the group’s defensive puzzle and player development pushes this offense into point-machine territory, the Association’s next in line might force its way to the front.

But right now, the Pups are more sizzle than substance. There are so many paths forward, and only a few lead anywhere near the top. Swapping some potential for proven top-tier production could transform this team from a pesky David into an actual Goliath. Minnesota has some interesting opportunities ahead, but this internal surge needs an external push to handle the most daunting challenges.

Ideal Player: Jimmy Butler

Realistic Player: Nerlens Noel

More NBA articles on GYSN:

August 2: 3 NBA players with a no-trade clause

August 1: All 30 NBA starting lineups

July 31: Cavaliers Waived Dahntay Jones

July 28: Top 5 Point Guards in the NBA right now

July 28: Durant told Westbrook that he was staying

July 27: Amar’e Stoudemire retires after 14 seasons

July 26: The reason why the King is still a free agent!