The Blue Jays on Wednesday placed Nate Pearson on the injured list with a sore right elbow, a major blow that comes just after Pearson struggled with his control on Tuesday night against the Orioles.

Pearson, Toronto's No. 1 prospect, hadn’t experienced this tightness before, manager Charlie Montoyo said early Wednesday, but he brought it to the club’s attention immediately after his start.

“He let us know that he was feeling tight,” Montoyo said. “It was kind of good news this morning that he was feeling better this morning, but of course he’s one of our big prospects, so we’re going to be careful with him.”

The Blue Jays are now without their best pitching prospect in Pearson, best hitter in Bo Bichette (sprained right knee) and best reliever in Ken Giles (strained right forearm) as they work to fight their way back into the playoff picture entering September.

Pearson didn’t quite look like himself on Tuesday, when he allowed five runs over four innings and struggled with his control, walking three batters. Most noticeable was his hesitation to lean on his elite fastball, which he threw on only 42 percent of his pitches, instead opting for his slider and curveball more often.

Montoyo said after the start that Toronto needs Pearson to attack more and get ahead in counts, but this news adds some potential context to that.

At this point there is no timeline for Pearson, who has a 6.61 ERA over his first four Major League outings.

“We’re going to go through all the tests to see where we are,” Montoyo said.

With Pearson on the IL, the Blue Jays can balance their rotation partly with the return of right-hander Trent Thornton, who’ll be used along with Chase Anderson in Thursday’s doubleheader against the Phillies. That means that when Pearson’s spot in the rotation comes back around, Toronto expects to roll with a “bullpen day.”

A bullpen day for the Blue Jays won’t be a string of nine single-inning relievers, though, thanks to such young starters as Thomas Hatch and Anthony Kay, who can eat multiple innings in a piggyback setup. That will put pressure on the club’s bullpen management, though.

In a corresponding roster move, right-hander Jacob Waguespack was added to the roster from the taxi squad.