His fastballs began in the 88-89 mph range. But Chris Sale was just getting into his bullpen session at Hadlock Field on Tuesday afternoon.

Red Sox pitcher Chris Sale stretches his left arm while speaking with Sea Dogs pitching coach Lance Carter Tuesday at Hadlock Field. Kevin Thomas photo

When Portland Sea Dogs left-handed hitter Ryan Fitzgerald stepped into the batter’s box, Sale, a 6-foot-6 lefty, came with a slider and then another.

“Today, I had a really good feel for it,” Sale said later.

Fitzgerald agreed.

“The first one I saw, I kind of buckled,” he said.

Fitzgerald would have liked a chance to actually hit against Sale, but Fitzgerald and other Sea Dogs acted simply as props, standing in their stance at the plate, bat in hand but not swinging – as Sale gets accustomed to pitching again.

“Each time I get on mound, it’s exciting,” Sale said.

Sale, 32, continues his rehab after having Tommy John surgery 15 months ago, a comeback that could return him to the Boston Red Sox within 3 to 4 weeks. This was his second bullpen session. After throwing 40 pitches last Friday in Worcester – Boston’s new Triple-A affiliate – Sale threw 45 pitches on Tuesday, in two “innings” of work.

“Building up. Keep stacking bricks on top of each other,” Sale said.

Sale will stay in Portland, working out, until returning to Boston on Friday.

Red Sox Manager Alex Cora said before Tuesday’s game in St. Petersburg, Florida, that Sale would face live hitters on Saturday.

Eventually, Sale will embark on a rehab assignment. That could land Sale back at Hadlock around July 6-11 (Worcester is on the road that week).

This week is Sale’s first in Maine.

“The drive in was nice. I told my wife it smells like Christmas trees,” Sale said.

Sale got to work Tuesday, initially playing long toss in right field with Sea Dogs catcher Oscar Rangel, before coming to the mound, amping up his fastball up to 92 mph, along with his slider and change-up. Sale’s approach looked more intense than a usual bullpen session.

“I have to, to get a good read on this; you have to test it and see where you’re at,” Sale said “I can’t go 75 percent and all of a sudden, those lights go on (in a real game).

“It’s nice to be aggressive with my arm action and see what the shape of my pitches will actually be like.

“Today, I was happy. Today was my best secondary-pitch day. Not to say my fastball wasn’t coming out good, but it was the best feel I had for my breaking ball. It was a little hit and miss (the last time out).”

An American League scout watched from the stands and said Sale “looked good. Still has a lot of life coming out of his hand.”

Still, the Red Sox won’t rush Sale, especially in the wake of New York Mets All-Star Noah Syndergaard’s setback from his Tommy John comeback. Syndergaard was making a rehab start in the minors last month and was shut down with right elbow inflammation.

“Obviously, what happened with Syndergaard is unfortunate. He and I got (injured) at the same time,” Sale said. “I really haven’t thought about (it happening to himself), to be honest.

“For me, I got to take care of myself, focus on my rehab. I can’t have that in the back of my mind.”

What is on Sale’s mind is pitching in the majors again for the contending Red Sox.

“That makes it more fun, but (for now), a little bit harder. You want to get out there and be a part of that,” Sale said. “I know I have some things to do to take care of myself, to be able to take care of my team.”