When the Boston Red Sox open the 2015 season in Philadelphia on April 5, they figure to face left-hander Cole Hamels.

Had things worked out differently, Hamels could have been pitching FOR the Red Sox that day.

Instead, the two sides couldn’t get together on a deal — reportedly because the Red Sox wouldn’t talk outfielder Mookie Betts or catching prospect Blake Swihart — and Hamels is still in Philadelphia, hanging in limbo as he and the baseball world await a deal.

Not getting Hamels left the Red Sox without a true ace — and apparently with the enigmatic Clay Buchholz at the top of the rotation and likely Opening Day starter.

The right-handed Buchholz has been an All-Star twice. He is 66-44 lifetime. But there have been injuries, problems that lingered longer than the team expected. And last year, when the Red Sox again fell to the basement, he went 8-11 with a 4.21 ERA.

Now, as the season begins, Buchholz is the closest thing the Red Sox have to an ace.

On St. Patrick’s Day in Fort Myers, Buchholz gave up four runs in four innings against the Atlanta Braves. But he also struck out six and the talk was positive after the outing. Only two of the runs were earned and his spring ERA is 1.80.

“I feel pretty good actually,” Buchholz said after the game. “I trained pretty hard this offseason to come to camp somewhat ready and the training and everything’s paying off being here. Been working out, it’s been pretty hot the last week or so, getting used to that and sweating a little bit.

“Overall, feel like arm’s in good shape. Just gotta continue to work on some little minor adjustments throughout the delivery and hopefully all that comes together before the start of the season.”

Buchholz was also pleased because his changeup was back, saying, “Today it was probably the best changeup I’ve had since 2013 on a consistent basis. That and the curveball, just about all my off-speed pitches, were where I wanted them to be.”