Aaron Sanchez's move to the Blue Jays bullpen inevitable

Despite a strong start to the season in the Blue Jays rotation, it's only a matter of time until Aaron Sanchez returns to the bullpen.

And it's all about the innings pitched.

On Tuesday's Baseball Tonight podcast with ESPN's Buster Olney, Toronto Blue Jays manager John Gibbons said: "We're still in discussion right now what that actual number is before we bump him to the 'pen, but it's gonna happen."

The Jays couldn't ask for a better start from Sanchez. The right-hander is 6-1 with a 3.38 ERA in 13 starts. The Barstow, Calif., native's 83 strikeouts in 85 1/3 innings is good for seventh most in the American League.

Despite a strong start, the Jays brass decided that they'll move him into the bullpen where he has been effective as a set-up man. Gibbons maintained the decision is all about health as Sanchez has never surpassed 100 innings pitched in his brief big-league career.

Past innings limits

The move is not without precedent. Both the Washington Nationals and New York Mets have shut down their own prized pitching prospects in recent years. 

The Nationals put a halt to Stephen Strasburg's 2012 season after 159 1/3 innings pitched as a precaution to the Tommy John surgery he underwent the year, despite Strasburg's success and the team in a pennant race. Strasburg has remained relatively healthy since, making 100 starts in the following four seasons with a 43-27 record.

In 2015, the Mets were facing the same dilemma as they had to balance Matt Harvey's long-term future and the team's post-season aspirations. The New London, Conn., native had missed the entire 2014 season recovering from Tommy John surgery.

To manage his innings, the Mets used a six-man rotation and planned on capping his innings around 185-190 in the regular season to allow him to pitch in the post-season. Harvey wound up pitching 189 1/3 innings in the regular season and an additional 26 2/3 in the Mets' run to the World Series.

The seventh overall pick of the 2010 MLB draft is 4-8 with a 4.66 ERA in 13 starts this season.

Potential replacements

When the Jays move Sanchez to the bullpen, the most obvious choice to replace him is either Jesse Chavez or Drew Hutchison. 

Acquired from the Oakland Athletics in the off-season, Cavez came into spring training fighting for a spot in the starting rotation. The 32-year-old has been one of the more steady arms in the Jays bullpen, posting a 2.59 ERA in 23 appearances.

The six-foot-two right-hander made 47 starts for the A's in the past two seasons with an ERA of 3.91.

Hutchison was 13-5 with the Jays last season, but 5.57 ERA saw him left off the team's post-season roster. With the exception of one start with the Jays this season, the 25-year-old has spent the entire season with Triple-A Buffalo where he is 3-3 with a 3.12 ERA in 12 starts.

Other internal candidates include Chris Leroux, Wade LeBlanc, and Roberto Hernandez, formerly known as Fausto Carmona. Leroux is without an MLB start in 65 career games but has made 10 starts with the Bisons this year.

LeBlanc leads the Triple-A International League with a 1.51 ERA, while Hernandez has started 217 games during his decade-long career.