Tyler O’Neill (right knee inflammation) received a cortisone shot in his injured knee on Thursday, which he said has already helped a lot. The Red Sox outfielder now expects to rest for a couple more days before potentially returning from the injured list on Wednesday.

“I’m hoping to come off in the minimum amount of days,” O’Neill said. “I’ve made a lot of progress the last couple of days so I like where I’m at.”

O’Neill said the injury had been nagging him for a while, and though it was manageable for a time things eventually deteriorated to a point where “it was getting a little ridiculous.” After batting .320 with nine home runs in March and April, O’Neill batted .151 with two homers in May and went 0 for 15 with 10 strikeouts in his last four games prior to hitting the IL.

“It got to a point where it wasn’t something I could play through, it was really affecting my performance and that’s not good for the team and it’s not good for me,” O’Neill said. “I feel like I’m making the improvements that I need to make finally, I’m not walking around with pain every day and stuff, so that’s a good feeling.”

When healthy O’Neill has been one of Boston’s best hitters this season, and since he began to struggle the offense’s production has notably dipped. In March and April the Red Sox averaged 4.76 runs per game, but since the start of May they’ve averaged more than a full run less at 3.74.

Extra innings

Isaiah Campbell (right shoulder impingement) is expected to make his fifth rehab appearance Saturday in Triple-A. Cora said he’s scheduled to throw two innings for the WooSox and that he will likely need at least another rehab outing afterwards. … Triston Casas (torn cartilage in left rib cage) is feeling great and had a doctor’s appointment on Thursday, but Cora isn’t sure when he’ll be cleared to start swinging a bat. “Hopefully that step is soon,” Cora said.