SEATTLE -- With 34 pitchers used, a thin rotation and the opener strategy becoming more common as the season goes on, somebody has needed to do the heavy lifting in the Blue Jays’ bullpen.

That’s fallen on Tim Mayza, who ranks second in the American League with 61 appearances going into Saturday's game, and Sam Gaviglio, who is set to make a run at pitching 100 innings out of the bullpen in 2019 with 80 1/3 under his belt so far.

This wasn’t the plan five months ago when the season opened, said manager Charlie Montoyo, but the realities of the season have brought them here.

With a heavy workload comes careful planning, from arm care to weight-lifting schedules. Mayza and Gaviglio have also coined a twice-weekly session that’s caught on with some of their teammates

“Tuesdays and Fridays, Sam and I joke, we call them R&D days, research and development,” Mayza said. “Those days are maybe a time we’ll get off the mound for 10 pitches just to work on that slider a little bit, without having the game intensity and the pressure of the game. So you have a little bit of a side [session] to throw 10 [pitches] off the mound and get a feel for that arm slot.”

This can mean different things for different pitchers. For some, like Mayza (“Mayz” for Players’ Weekend), this is when the advanced technology comes out to break down arm angles, spin rates and the finer points of delivery. Others, like Gaviglio (“Sammy G”), still rely on feel, and use these sessions to build consistency.

Physically, it’s been a new challenge. Mayza has made some slight adjustments to his workout routine, but is pleased with how his body feels. There has been some consistency to the timing of his outings, though, which is a routine that Mayza has been able to settle into. Gaviglio’s outings come less often but encompass more innings, which means he’s had to adjust his rotating leg workouts and upper-body days, but if he pitches three innings on a Monday, then it’s easy to schedule those heavier workouts for the Tuesday, knowing he’s unlikely to be used.

“Overall, it can get a little taxing, and bouncing back becomes a little more difficult,” Gaviglio said, “but overall, where I’m at right now, I’m feeling pretty fresh.”

Stewart added back to roster

Brock Stewart was recalled from Triple-A Buffalo prior to Saturday’s game against the Mariners and is expected to be used at some point following opener Wilmer Font. Stewart has made two appearances for the Blue Jays since being claimed off waivers from the Dodgers. In 9 1/3 innings, he's allowing three runs, all on solo homers.

In a corresponding move, infielder Richard Ureña was optioned to Triple-A.