Will the real Aaron Sanchez please show up?

Coming into the season, the Toronto Blue Jays starting rotation was supposed to be its strength. Six weeks into it, it’s anything but. As of May 18th, they’re 22-23 after a 13-6 start to their season. With the fifth-most home runs and runs scored, the offense has been better than expected while their bullpen has pitched 159.1 innings with a 3.22 ERA and 3.85 FIP.

They were able to win a bunch of games early in the season when offense carried them through. It was also reasonable to expect that with offense regressing somewhat, the starting rotation would soon find its bearings and would be able to put better numbers. That has not happened! And with offence and relievers slowing down, the rotation has not been able to put its hand up and the team is in a rut where the players called for a players only meeting before the game on May 18th.

Aaron Sanchez is a headline piece of this rotation. After spending most of 2017 on the DL it was expected that he would return to his ERA title form from 2016 and help settle the top of the rotation with Marcus Stroman and J.A. Happ. However, to say that he has had an inconsistent start to the year is an understatement. As of May 18th, Sanchez has pitched to an ERA of 4.47 and a FIP of 4.93 in 50.1 innings. Although his strike outs per nine and ground ball rates remain steady, he’s walking a whopping 5.19 batters per nine innings.

Sanchez has made some major adjustments to his pitching mix this year. He’s throwing far more change ups vs curve balls. This is interesting as the curve ball has always been Sanchez’s go to pitch - in 2016 - his first full year as a starter - batters’ ISO against his curve ball 0.094 and .145 BAA. Here’s his pitch mix in 2016 (data: brooksbaseball)...

...and here’s his pitch mix thus far in 2018:

Sanchez is using his change up 3.5 times more than he did in 2016 which he has thrown his curve ball only half as often than 2016. Part of that could be that Sanchez now has an improved change up which allows him to throw it more often and hence not show his curve ball as often.

brooksbaseball.net

It has been speculated that Sanchez hasn’t thrown curve balls as often because of his issues with blisters last year. Although it may be partially true, I would argue it has more to do with his change-up’s development more than anything else.

However, it’s not these two pitches which is the primary cause of Sanchez’s troubles. Batters are hitting .295 against his sinker and have an ISO of .269. He has also lost a couple of miles on his hard pitches which according to Sanchez is deliberate. What this has resulted in is that hitters are able to pull more than they’ve been able to in the past. They’re also able to hit more fly balls per balls in play on his sinker - 18.57 - than they did in 2016 - 13.77. This number looks more magnified if we isolate just right handed batters.

Traditionally, right-handed batters have found it tougher against Sanchez. This year, however, they’ve been able to pull the ball with more power (0.278 in 2018 ISO vs 0.102 ISO in 2016) despite a similar average (0.239 in 2016 and 0.241 in 2018). Right-handed batters are hitting 20.83 FB/BIP this year, resulting in more balls being pulled with authority.

There could be a bunch of different reasons why this is. Firstly, it could just be that it’s such a small sample size and his numbers will correct before the year’s out. Secondly, it could be that Sanchez is still trying to find his feet after a long lay off last year and hasn’t shaken off rustiness, or it could be that his command is off as he’s missed his location down in the zone more thus far. Here is the zone profile for sinkers from 2016 and 2018:

What ever the reason being, it is imperative that for his and especially for the Blue Jays season, Sanchez figures it out sooner rather than later.

Azam Farooqui is a contributor at Beyond the Box Score. You can follow him on Twitter at @afarooqui21