Their season alive only mathematically, the Islanders start counting down their final 10 games when the league-worst Penguins visit Nassau Coliseum tonight.

The Isles will seek to rebound from Wednesday’s 5-1 loss to the Rangers at the Coliseum, a defeat that left them 10 points out of the final Eastern Conference playoff berth entering last night.

They’ll also try to atone for blowing a lead to fall to the Penguins on Sidney Crosby’s overtime winner last week, a loss that pulled the plug on any realistic remaining playoff hopes.

Although it won’t help them this season, the Isles yesterday signed 2005 first-rounder Ryan O’Marra (15th overall) from Erie of the Ontario Hockey League. A center, O’Marra has been assigned to the Sound Tigers.