Time is like a freight train. It’s unstoppable. And it only gets louder when passing you by.

Cardinals quarterback Drew Stanton is trying hard not to listen.

“I came to Arizona with the mind-set of being the starter,” he said. “But the important thing is the approach and the professionalism that goes along with this job. That’s what I have to focus on.”

Once again, Stanton has been relegated to the role of backup quarterback, a tough-luck quarterback. He’s played in 13 games over five NFL seasons, starting four of them. He remains one of the NFL’s great unknowns.

Experts say he has the size, skill and intelligence to run his own team, to hold one of the 32 more-coveted jobs in sports. The Jets called him an “ascending” player after signing him in 2012. Yet he hasn’t seen the field in two years. And each time the window of opportunity opens, it slams down on his fingers.

“My wife and I talk about it often,” said Gaylord Stanton, Drew’s father. “We wonder if we cursed our child.”

The elder Stanton is half joking. But six years ago, his son was a second-round pick from Michigan State, part of Matt Millen’s last draft class in Detroit. A local newspaper suggested Stanton could be the Lions’ first hometown quarterback since Gary Danielson in 1976.

Back then, no one could hear the clock ticking. And Stanton’s parents were most concerned for their son’s safety.

“If Drew wanted to be a backup quarterback for 15 years with his cap on backwards and holding a clipboard, I’d be OK with that,” his father said at the time.

Today, those words are taboo in the Stanton household.

“His mother still feels that way,” Gaylord said. “But I don’t. Now I want to see him get his chance.”

This is clearly a touchy subject back home. To wit:

When former New York General Manager Mike Tannenbaum signed Stanton before the 2012 season, he slotted the quarterback as the unquestioned backup to Mark Sanchez. The Jets reportedly told Stanton they were not in the market for any other quarterbacks.

Days later, abruptly changed directions, acquiring Tim Tebow.

Stanton was quickly traded to the Colts, where he ran the first team while Andrew Luck finished up at Stanford. It was enough time to make a really good impression on the coaching staff, and then it was back to the sidelines.