This could make for an uncomfortable family reunion.

An adviser working for the hedge-fund manager who sued the New York Islanders for reneging on a deal to sell him the team is NHL Commissioner Gary Bettman’s half-brother, The Post has learned.

Andrew Barroway hired Jeffrey Pollack several months ago after reaching a handshake deal to buy the club from owner Charles Wang for $420 million, sources said.

Wang and Bettman are believed to be pals.

Barroway also hired David Carlock, a sports-marketing specialist, as a late addition to help in his Islanders bid — which ran into trouble, sources said, when the Philadelphia lawyer and hedge-fund executive had trouble raising the money needed for the purchase.

Barroway says he had the funds.

Wang in mid-July unexpectedly raised his asking price for the team from $420 million to $548 million, making it nearly impossible for Barroway to complete the purchase, the lawsuit claims.

As for Pollack, the Barroway gig is believed to be the first time he advised on the sale of an NHL team.

To buy an NHL team, a bidder would have to win the confidence of Bettman and most of the team owners.

Pollack, 13 years Bettman’s junior, is best known for being the former chief executive of the World Series of Poker. Over the last four years he has been a sports and entertainment adviser and helped Robert Pera in 2012 buy the NBA’s Memphis Grizzlies.

Barroway was introduced to Pollack by someone who met the adviser during the Grizzlies purchase, a source said.

Neither Pollack nor the NHL returned calls for comment.