Training camp rolls on and the competition for NHL roster spots continues, for many of the Islanders prospects they are still a few years away from either making the big club or from the team having to decide whether or not to cut ties with them. For a trio of Islander defenders -- Matt Donovan, Calvin de Haan and Aaron Ness -- this year could be their last shot at making the NHL with the Islanders. For all three players, their entry level contracts will expire at the end of the season. That puts them into a tricky territory of being restricted free agents who don't have arbitration rights. For many players in that situation with the Islanders the last few years, they've had to seek work in Europe because the Islanders retained the player's rights with a qualifying offer at the end of the season, but the player walked away from that offer and the team didn't come back with a better one.Last year, David Ullstrom fell into this category. Ullstrom was a marginal NHL winger for the Islanders, and the team tendered him a qualifying offer at the end of the year. Player and team couldn't come to an agreement, so after three years in the Isles organization, he's headed to Russia. Justin DiBenedetto, Mikko Koskinen and Rhett Rakhshani are other players who fell into this category in recent years. The Islanders retain all of their rights until they become UFA at 27 years of age (that's why you still hear their names from time-to-time), so they either have to accept the QO and play in Bridgeport or head overseas.Would Donovan fall into this category? It's unlikely. The Islanders would likely be interested in keeping the talented defender in Bridgeport if he doesn't make the team and give him a decent offer and the player, who is still pretty young, would probably stick with the program. He was an AHL All-Star last year and had the inside track for making the team since the summer and was paired with Andrew MacDonald last night. He's certainly a defender the Islanders value.But, with players such as Scott Mayfield, Andrey Pedan, Ville Pokka, Adam Pelech, Griffin Reinhart and Ryan Pulock all either in Bridgeport or going to be there in the next year or so, the Islanders are going to have the luxury of picking and choosing exactly which defenders they want to build their NHL roster with. It's a great problem for the team and a tough one for the players.Would that excess of defenders mean parting ways with a first round pick who has run into a plethora of injury trouble such as de Haan? It's not out of the question. If after three years, multiple shoulder injuries and -- we'll assume for the sake of argument -- not making the team, it could finally be time to cut ties with the tough-luck defender as so many top prospects are waiting in the wings. After trading up to select him back in 2009, it would be the second failed first round pick of Garth Snow's tenure, behind arguable Nino Niederreiter. Sometimes it's not the players talent that causes things to not work out, it's just the circumstances and that could certainly be true in the case of de Haan.For a player like Ness, who is already on the back burner when it comes to discussion about who is going to fill out the NHL roster this year his fate may already be sealed. He's already behind Donovan and Thomas Hickey for "small, pucking moving defender" and the tons of prospects behind him will only make things worse.The Islanders have some decisions to make about which defenders they want to keep on the NHL roster for opening night, and there are some other important decisions to make about those defenders down the road. For this trio, it could be their last NHL training camp as Islanders prospects. For Donovan, that may mean he'll be back at Islanders camp next year as a bona-fide NHLer. For de Haan and Ness, the future isn't quite so clear.