Almost as soon as Jets ownership’s announcement of the contract extensions for coach Todd Bowles and general manager Mike Maccagnan were made Friday, their players rejoiced and, in unison, talked about how “close’’ the team is to being a true playoff contender. Tight end Austin Seferian-Jenkins went as far as to say that teams are “afraid’’ to play the Jets. “They’re not like, ‘Oh God, we’re playing the Jets, they’re going to be a pushover,’ ’’ Seferian-Jenkins said. “They know that when they come to play us it’s going to be a really tough game.’’ Well, the oddsmakers in Vegas disagree with regard to Sunday’s regular-season finale between the 5-10 Jets and 12-3 Patriots at Gillette Stadium, where the Jets are 14¹/?-point underdogs and not expected to be competitive in a game New England needs to win to secure home-field advantage throughout the playoffs. “I think not only do we know, but everyone else knows after this year that we are a good team,’’ defensive lineman Leonard Williams said. “I think we’re pretty close,’’ receiver Jermaine Kearse said. “I just got here [this season] and I like what I see.’’ Well, Sunday against the Patriots would be a good place for the Jets to prove how good they think they are despite their poor record, prove how “close’’ they are to being a playoff contender. They can do that by defeating the defending Super Bowl champions, who have won the last three meetings between the two teams, six of the last seven and 11 of the last 13.