Colin Campbell admitted what was fairly obvious to those who watched Wednesday's contest between the Atlantic Division rival Philadelphia Flyers and Pittsburgh Penguins.

Danny Briere was clearly offside prior to scoring the first of Philadelphia's four unanswered goals during Game 1 of the Eastern Conference quarterfinal series.

Linesman Tony Sericolo failed to make the call despite being in position, the NHL's senior executive vice president of hockey operations said.

Briere tallied again and the Flyers rallied for a 4-3 overtime win to take the lead in the series.