The Toronto Blue Jays are set to get a massive boost to their pitching rotation and depth on Friday, when former Cy Young winner and trade deadline addition Shane Bieber makes his team and season debut against the Miami Marlins.

Bieber, 30, was acquired in a deal with the Cleveland Guardians on July 31 while in the midst of rehabilitating from Tommy John surgery on his pitching elbow in 2024.

Bieber made seven rehab starts, with his most recent offering a glimpse into the potential of the former ace - he threw seven innings of shutout ball on Aug. 15 against the Philadelphia Phillies' Triple-A affiliate.

His introduction has given cause for excitement for Jays fans in the midst of a promising campaign with the team is holding a 4.5-game lead over the New York Yankees in the American League East division standings with fewer than 40 games remaining on the schedule.

But it also provides a difficult task for Blue Jays manager John Schneider. He and his staff have to figure out how to optimally use the now six healthy starting pitchers on the roster when standard practice in the majors is to operate with a five-man starting rotation.

Bumping a starting pitcher to the bullpen

Schneider has already made his initial decision, as lefty starter Eric Lauer was sent to the bullpen for the upcoming weekend series against the Marlins.

Lauer was scheduled to pitch on Friday before the decision was made to give Bieber the start instead. Schneider told reporters that this is not a permanent solution to the problem earlier this week.

"This is not a [permanent] move to the bullpen," Schneider said.

Lauer has been arguably the best starter for the Blue Jays this year, with a 2.76 earned-run average and an 8-2 record in 20 games (14 starts). Lauer spent last season pitching in the KBO after flaming out of the majors, but has had a career year in his return with Toronto.

In his six relief appearances this season in Toronto, Lauer has pitched to a sparkling 0.96 ERA over 18.2 innings. Of the other five pitchers in the rotation - Bieber, Kevin Gausman, Jose Berrios, Chris Bassitt and Max Scherzer - there isn't a lot of bullpen experience to draw a conclusion from.

Since the 2020 season, three of the five have made an appearance out of the bullpen in some fashion: Bassitt (once earlier this year), Gausman (twice in 2020) and Scherzer (once in the 2021 postseason).

Blue Jays pitchers' results by role since 2020

 
Pitcher Starts Innings pitched ERA Relief appearances (playoffs included) Innings pitched ERA
Kevin Gausman  161  935.0  3.38  2  5.0  3.60 
Jose Berrios  166  955.1  3.98  -  -  - 
Chris Bassitt  159  917.1  3.59  1  1.0  0.00 
Max Scherzer  112  647.0  3.07  1  1.0  0.00 
Shane Bieber  82  514.0  2.91  -  -  - 
Eric Lauer  74  382.2  4.05  13  41.1  2.83 
 

One of the prime fears when moving a starting pitcher to the bullpen is a loss of routine, which can knock a pitcher out of their groove. Primary relief pitchers are used to entering a game on a dozen or so pitches of warmup in a pinch, while starters tend have an established routine before entering a game and working for many innings.

Of the six options, Lauer has the most bullpen experience by a wide margin, but he also has the best ERA this season (2.76).

Moving to a six-man rotation

The other option for the Blue Jays is to have six starters take a regular spot in the pitching rotation.

Over the next few weeks, the Blue Jays are scheduled to have two separate instances in which they play six games followed by an off day, which would allow for a natural progression through a six-man rotation.

The other component to that argument is the fact that it will keep the veterans healthy. Each of the six pitchers slated to take a spot in the rotation is older than 30 years, with Bassitt (36) and Scherzer (41) both north of 35 years old.

Veteran pitchers tend to have injuries pop up more frequently than their younger counterparts - Scherzer has already missed an extended period of the season due to a ligament issue in his pitching thumb, while Bieber is obviously returning to the rigors of pitching in the season after a lengthy absence due to recovery from elbow surgery.

Another component to consider is the role of routine in terms of start dates. Some pitchers stay sharper when given four days of rest between starts. Whether it be due to wear or superstition, sometimes pitchers can struggle or excel after an extended layoff between starts.

Blue Jays pitchers' results by days of rest between starts

 
Pitcher Days of rest Starts ERA Days of rest Starts ERA Days of rest Starts ERA
Kevin Gausman  4  7  1.61  5  13  5.94  6 or more  5  2.16 
Jose Berrios  4  9  3.83  5  14  3.78  6 or more  3  5.63 
Chris Bassitt  4  13  4.75  5  11  3.79  6 or more  2  3.00 
Max Scherzer  4  4  3.27  5  4  2.52  6 or more  3  6.23 
Eric Lauer  4  6  3.41  5  6  3.38  6 or more  2  2.45 
 

Pitching on different levels of rest has yielded varying results for Jays' pitchers this season, with some broad conclusions to be found: Bassitt has performed worse with less rest between starts, while Scherzer and Berrios have performed significantly worse with more than five days of rest between appearances.

It's a tough balancing act for the manager, especially given the spread out schedule during the playoffs.

Lauer summed it up Schneider's position nicely when he commented on his move to the bullpen earlier this week: “It’s going to be interesting," Lauer told reporters. "I’m glad I’m not the one making the decisions."