Antwan Barnes remembers being especially happy one day in January while visiting Las Vegas ... until his phone rang.

“My mom was actually the one who called me” the Jets linebacker said recently. “When I heard her crying on the phone I knew it was something bad. I just had to return back to Florida.”

Chandler Williams a 27-year-old college teammate of Barnes had dropped dead playing flag football in Miami. For Barnes the emotions ranged from shock to disbelief to terrible sadness. He had known Williams since high school when they played against each other.

They would go on to Florida International to play together. They became the first two players drafted from the college in 2007 with Barnes going in the fourth round to Rex Ryan’s Ravens and Williams taken in the seventh by the Vikings.

Barnes went on to play for the Chargers and signed with the Jets this offseason. Williams bounced around the NFL spending time on the practice squads of the Dolphins Falcons and Chiefs. He also played in Canada and the Arena League.

Williams was participating in a flag football tournament when he dropped to the ground and could not be revived. The doctors said his heart gave out.

“They said he must have had warning signs that he ignored” Barnes said.

Barnes flew home to attend the funeral and see Williams’ mother wife and 2-year-old daughter.

They all tried to wrap their heads around how an athlete who was not yet 30 could die of a heart condition.

“He was the most in-shape guy you’d ever meet” Barnes said. “He was the type of guy who could go through practice and then go play a couple of pickup games of basketball with no problem without ever being tired. Just hearing that it makes you think to watch out for anything and go get yourself checked out.”

Barnes now is carrying Williams’ legacy with him. He wears a shirt underneath his pads during practice with a picture of Williams and wings behind him. It says “I am my brother’s keeper” on it. Barnes said a friend made a few of the shirts for him just before training camp. He also has another version of the shirt he will wear on game days under his pads.

“Most definitely” Barnes said when asked if he is playing for Williams. “Just because he was my FIU brother.”