The Marlies will be a whole new team next year. With several of the top prospects expected to move up to the NHL, there will be a lot of openings. While Kasperi Kapanen and Andreas Johnson will likely be back for more AHL action, William Nylander, Connor Brown, Zach Hyman and Nikita Soshnikov likely will not be.

As tempting as it is to believe it, you cannot have a successful AHL team as a U23 club of NHL prospects. You need more experienced players who form the backbone of the team.

This year's Marlies, with their massive number of wins and huge goal differential, got there with a one-two punch from what a lot of fans call tweeners or AAAA players, one of whom is gone already and one who is a UFA.

A lot of Marlies are UFA or RFA, and that lack of core players who knew for sure they had a future with the organization may have hurt them in the playoffs. They had the experienced core to rely on, but for some of those players, maybe it felt like their time on the Marlies was already their past.

The free agent Marlies won't all follow Mark Arcobello off the team, some of the youngest RFAs are likely to be back, but he won't be the last to leave either.

Mark Arcobello

Arcobello was the top scoring forward on the team, and a man who thought he would be playing in the NHL when he signed his contract last summer. He will be playing next year for SC Bern in the Swiss league.

He played 64 games on the Marlies, all 15 playoff games, was the top centre most of the time, anchored the top power play unit, played big minutes and leaves half of the biggest hole the Marlies have to fill.

In-house candidates to fill it are scarce. Restricted free agent Colin Smith might be an option, but at 22, he lacks the depth of experience Arcobello brought. Finding a high-level scoring forward who is not a rookie and who will play hard for your AHL team when he is qualified for a higher paying job elsewhere is not easy. The Marlies got lucky with Arcobello, and they may not be able to find just one guy who brings that full package to the team. They had better find more than one guy because they need to fill Nylander's spot too (the other half of the big hole).

T.J. Brennan

Top scoring player on the team, Brennan had a career year in the AHL and a fairly disastrous trial in the NHL. Any hopes of NHL play might be over, and for a UFA of his age, the time is now for him to decide where he wants to go with his career.

Europe is the obvious choice. He is likely more than enough for a lot of KHL teams and could be a star in lesser leagues, but he may wait until July 1 to decide where he wants to go.

His place on the team is less difficult to fill, although it is unlikely any candidate will score quite as much as him—defencemen don't challenge for the league leads in points too often.

The Marlies have already started filling his place with the reported signing of Nikolas Brouillard to an AHL contract. He is a fast-moving, high-scoring junior defencemen who just finished playing in the Memorial Cup final.

Who else they will have on the defence corps is a good question. Andrew Campbell, Rinat Valiev and Viktor Loov are all under contract for next year, and decisions on RFAs Scott Harrington, Frank Corrado, Connor Carrick, Martin Marincin and Stuart Percy will need to be made. In addition, Andrew Nielsen and Travis Dermott are signed to contracts and could join the team next year.

None of those players, with the exception of Carrick who will likely play in the NHL, has shown the scoring ability Brennan has.

Ben Smith

This late addition to the Marlies is more NHLer than minor leaguer. He played a few games for the Sharks organization in the A, but he looks like he fits on an NHL third or fourth line very comfortably.

In the AHL, he is overpowered for the state of play, and can play up and down the lineup effectively.

As a UFA, he will be looking for an NHL gig come July 1, and he will likely find one.

He did not play a lot of regular season, but he was crucial in the playoffs, easily supplanting Frederik Gauthier or Sam Carrick. Rather than leave a hole to fill, he illustrated the gap between those players and someone ready for NHL work on the bottom six.

Rich Clune

Clune was the quintessential role player for the team. He wore the A, he played on the fourth line where he got into trouble less than almost every AHL agitator or tough guy on any other team, and he helped make Nikita Soshnikov into the miniature Leo Komarov he is today.

Clune is also very close to being an NHL level depth player. He would need to rein in his borderline hits, take fewer penalties and play with the puck at his top level of ability a lot more, but he could do it.

He could also be a good returning core player for the Marlies, but he might not want to settle for that role without testing the UFA market first.

If he leaves, the Marlies have another big hole to fill. They have no one else who does what Clune does, and until the AHL really changes to a league where that forearm shiver on Kapanen in the playoffs gets you suspended, they will want someone who does do what he does, no matter how effective or ineffective of a deterrent frontier justice actually is.

Sam Carrick

RFA and late playoff healthy scratch, Sam Carrick reads like a player who is showing his peak ability in North American hockey. Colin Smith is younger, faster, better, and unless Carrick wants a career as an AHL bottom six player, his value to the Marlies and to the Leafs as one of only 50 SPCs is questionable.

He is a centre, and those don't grow on trees in quite the same numbers wingers do, but if Freddie Gautier is not ready to move up and take his place, than neither of them are who the Marlies need, forget about the Leafs.

With young rookies like Dmytro Timashov, Dermott, Nielsen and others possibly joining the team as well as Shayne Conacher and Mason Marchment, who were signed to AHL contracts recently, the forward ranks could get crowded, despite some of the expected departures.

Stuart Percy

Percy is a quietly effective defenceman who lacks in any wow factor to get him noticed. As one of a host of left-shooting defencemen, Percy is getting pushed down the depth chart from above rather than failing to rise. And now Broulliard is pushing from below.

His quiet effectiveness in the Marlies playoff run was easily eclipsed by Connor Carrick's loud points.

Connor Carrick, Nikita Zaitsev and Frank Corrado will be busy fighting for the right-side jobs on the Leafs with any of the better switch-hitters, and that leaves the big guns of Jake Gardiner and Morgan Rielly on the left. Martin Marincin has already established his bona fides and will likely be re-signed as well.

For Percy to take even an occasional third pair job seems unlikely given Rinat Valiev's position in the organization, despite the latter's poor showing in the AHL playoffs. There is also Scott Harrington to consider, who had substantial NHL time with good underlying numbers but missed most of the AHL season with an injury.

Percy could be a top candidate to be moved in a multi-player trade, which seems like an inevitable step this summer. Like turning the soil over before you plant a garden, clearing out the prospects at 22 or 23 is a necessary step in the growth of the organization, not just the Marlies.

While Kyle Dubas had said development doesn't have an age limit on it, there is yet to be any evidence presented that the Leafs are interested in investing beyond a single season in anyone older than 23 unless they are a sure NHL bet. There are always new prospects coming over the horizon; there will always be competition for spaces, and age will always be a factor that weighs heavily against a player, even defenders.

If a player has potential but there is no path open to move up, then keeping him might be the worst move for everyone. Players are not assets that sit quietly in a cupboard appreciating like your collection of mint hockey cards. They think for themselves, and if their path is blocked, and a team won't trade them, they will leave you with nothing to show for it.

Deciding when to pluck a prospect out of the garden and make way for new ones is merely the next step in player evaluation after draft picks are chosen. And it is as bad for an organization to hold onto prospects too long as it is to trade too many of them.

A full list of Leafs RFAs including those on the Marlies is available here.