Brayan Bello, who was Boston’s Opening Day starter last season, threw his first bullpen session of spring training on Friday. He is working his way back from a sore shoulder. Charles Krupa/Associated Press

FORT MYERS, Fla. — The Boston Red Sox didn’t want starter Brayan Bello to go 100% on Friday in his first bullpen session since returning from shoulder soreness . He said he was at 70-75% effort level.

“They told me to stay within 80-90 mph,” Bello said through interpreter Daveson Perez at JetBlue Park. “So just a very light session.”

Bello said he still should have enough time to be ready for the Opening Day roster.

“The trainers are telling me that I’m right on track as long as I just keep doing my work that I’ve been doing,” Bello said. “Just getting ready for that.”

Bello said he has to check in with the trainers on how many bullpens and live batting practices he’ll need before getting into Grapefruit League games.

“But I would think like a couple more bullpens, maybe a live BP before going into games,” Bello said.

Bello said he feels strong.

“The body’s good. The shoulders are good. The mechanics are good,” Bello said. “Just taking it day-by-day, but I felt good today.”

Bello was Boston’s Opening Day starter last year. He finished with a 4.49 ERA in 30 starts. He pitched much better during the second half, when he posted a 3.47 ERA and 3.68 FIP while holding opponents to a .219 batting average.

RED SOX OUTFIELDER Wilyer Abreu is still optimistic he’ll be ready for Opening Day.

The 25-year-old Abreu, who won a Gold Glove as a rookie last season, has been dealing with a viral gastrointestinal illness.

“I still have three or four weeks here where I can still get some good work in and be ready,” Abreu said through interpreter Daveson Perez on Friday. “The circumstances are what they are. But feel I still have plenty of time.”

Abreu is noticeably slimmer.

“I definitely lost a little bit of weight,” Abreu said. “But in all honesty, I think it might have helped me a little bit just because I feel I’m more in form than I was. I know it was a sickness, or whatever you want to call it, but I think that the weight loss has kind of helped me a little bit.”

The Red Sox were monitoring lab results before giving him the green light for baseball activities. Manager Alex Cora told reporters on Friday in Clearwater that Abreu has been cleared.

“Sooner than I think people think,” he said. “I think very soon I’ll be able to resume baseball activities.”

He was not impatient by his delayed start to spring training.

“I think I’m really calm right now,” he said. “I think the first thing, the most important thing, is just to focus on my health and getting better. Of course I want to be out there with my teammates and practicing together, being together. But right now the priority is my health.”

Abreu posted 17 defensive runs saved in 921 1/3 innings in right field last year.