Sources: Battle over Isles brewing

There's a potential battle brewing involving the New York Islanders and New York Rangers, and it isn't even on the ice.

A major selling point of Bruce Ratner's pitch to win the renovation rights to Nassau Coliseum is the promise to bring the Islanders back to the arena for a six-game slate after they move to Brooklyn's Barclays Center.

And while that would appear to be enticing to the Nassau County executives who are currently deciding among four bidders, it's not a promise Ratner necessarily can deliver.

According to multiple sources, both Madison Square Garden and the NHL would have to sign off on that scenario, and that is not guaranteed to happen.

Madison Square Garden, which owns the Rangers, is also among the four bidders.

"He made a promise that is not 100 percent in his hands," a person familiar with the situation told ESPNNewYork.com.

The league also would have to approve the six-game tour. It is not immediately clear whether it is open to doing that considering the seat capacity and potential revenue reduction that could result.

Barclays Center CEO Brett Yormark said he has informed the league about this plan in the case they are awarded the renovation rights, and he doesn't envision it being a problem.

"The NHL is a fan-friendly league," Yormark said when reached by phone Wednesday. "I'd assume they'll ultimately do what's best for the fans in Long Island."

According to NHL deputy commissioner Bill Daly, via a league spokesperson, the issue is an "internal matter upon which we are not commenting."

Although at least one league source doubted the capacity issues would be a deterrent -- "I don't think that would be a determining factor," the source told ESPNNewYork.com -- another person briefed on the situation believes otherwise.

That source said sacrificing revenue on those six games at Nassau, which is expected to hold a capacity of 13,000 fans after renovations, is a major concern.

Barclays Center, home of the Brooklyn Nets, is fitted to seat 14,500. Nassau, currently the oldest arena in the league, seats 16,170.

The Islanders signed a 25-year lease with Barclays Center starting in 2015, though there have been indications the team would like to move there sooner.

The consent needed from both the league and the Rangers is derived from Article 4.2 and 4.3 of the NHL's constitution, which deals with territorial rights of the league and of its members.