FORT MYERS, Fla. -- Watching Dustin Pedroia play this Spring Training, you get a reminder of what he was prior to 2017, when a problematic left knee all but ruined him for two years.

At the plate, Pedroia is routinely barreling up the baseball, even as he still tries to get his timing back after missing all but three games of 2018.

In the field, he is making plays and turning double plays with ease.

In the clubhouse, he is joking around again, though maybe not quite as boisterous as in the days of his youth.

The man who helped create his own nickname “Laser Show,” is now laser-focused on the biggest challenge of his career -- proving there is plenty of baseball left in him.

Pedroia is under contract for three more seasons, and he’d love to play those with a left knee that doesn’t hold him back.

As encouraging as the early signs are, nobody will know if it’s possible until Pedroia engages in the grind of the 2019 season.

His season will start a tad late. The second baseman will start the year on the injured list so that he can spend another week or so ramping up with his game progression. He could be back as soon as April 9, the day the Red Sox play their first game of the season at Fenway Park.

But for Pedroia, this season isn’t about coming back. It’s about staying back. More to the point, it is about staying on the field and out of the trainer’s room.

“When you’re coming back from something like this, no one thinks you can do it. If I’m not confident about it, it’s not going to happen,” said Pedroia.

The reason some are skeptical about Pedroia’s comeback is because the surgery that he had -- a cartilage replacement procedure -- is one that no position player has ever had before. Red Sox knuckleballer Steven Wright became the first baseball player to have that type of surgery just months before Pedroia.

At the beginning of Spring Training, Pedroia admitted that if he had to do it again, he would have selected another type of surgery or rehab.

But there is no turning back now.

Do the skeptics who don’t think Pedroia will make it all the way back drive him?

“No, not really. I enjoy playing,” Pedroia said. “I enjoy trying to set an example for my kids, things like that. That’s the stuff that drives me.”

Perhaps out of respect for Pedroia, what he has done and who he is, the Red Sox did not acquire a potential replacement for him in the offseason.

In Eduardo Nunez and Brock Holt, the Red Sox have two quality players who can fill in for Pedroia during that first stretch of the season when he is on the injured list. Tzu-Wei Lin will start the season in the Minors, but he’s another player that the Red Sox like in the middle infield.

Should Pedroia experience another long-term setback, president of baseball operations Dave Dombrowski would probably go shopping, like he did last year with the July 30 acquisition of veteran Ian Kinsler.

But for now, the Red Sox are all-in on Pedroia, even if he represents the great unknown of their 2019 season.