Aroldis Chapman is back with the Yankees, so what can fans reasonably expect?

For many Yankee fans, no player inspires more eye rolls than when Aroldis Chapman comes to the mound. In the last few years, he has defined the term mercurial. As he returns from the injured list after contracting a leg infection due to a tattoo, the question of what the Yankees can expect from him is entirely up in the air. The best that fans can do right now is look to Chapman’s most recent performance (fresh off the IL), and how he’s fared on the season as a whole.

In the losing effort on Saturday, Chapman pitched in the seventh inning. He was solidly OK in the outing. Of course, he walked the first batter he faced, but that eventually amounted to nothing. Chapman subsequently got two quick lineouts, and then struck out Christian Yelich to end the inning.

Even with a walk to begin the inning, Chapman managed to work a scoreless frame after returning from the injured list.

Credit: Baseball Savant

We can glean several items of note from Chapman’s appearance. The first is that his command and control of his fastball remains relatively fickle. It’s sometimes there, and it’s sometimes really not. It’s most evident with the fastball six feet in the air. Chapman’s fastball speed is also down a little bit compared to his season season average, despite the 99-mph heat to fan Yelich. His season average on the four-seamer is 97.6 miles per hour, while it only averaged 97.0 miles per hour on Saturday.

This all indicates that Chapman does not have the same premium velocity that he had in seasons past. This could be the result of the numerous ailments and injuries that he has suffered this year. At the same time, it might just be a continuation of the trend of losing velocity as he ages (though he was slightly up in 2021). Chapman was still able to reach 100.8 miles per hour on his fastball on one pitch — a ball that was not even close. In addition, his slider remains all over the place.

On the season, Chapman has pitched poorly for the most part. Whether this is through injury or age, his performance has not matched his previous abilities. In 31.2 innings across over 37 games, he has a 4.55 ERA with 36 strikeouts.

While posting more than a strikeout per inning remains relatively good, it does not nearly match Chapman’s career averages. This year, he is only striking out batters 25.7 percent of the time, while his career average sits at 38.4 percent of the time. This might be partly a result of inconsistent command and control of all of his pitches, but particularly his split finger and four-seam fastball.

Credit: Baseball Savant

This proves particularly problematic for Chapman, as he has always had an elevated walk rate. The high-strikeout percentage ensured that he could often get out of trouble by striking out the opposing batters. Unfortunately, his elevated walk rate remains with 23 walks in just 31.2 innings. Without the tremendous K numbers of his past, his ERA has suffered.

So how much should the Yankees trust Chapman going forward? The answer comes down to how much the team believes in his past performance. If they think that his injuries have caused the dip in pitching ability, and they believe that those injuries are behind him, then they might trust him considerably. A more cautious approach might be more appropriate.

While there were spurts of games where Chapman has pitched without allowing an earned run, there have been periods where he gives up one or more runs an appearance. He has just not shown enough consistency to warrant any large amount of trust. Even in the game on Saturday, his control and command were all over the place. The Yankees can instead ease him back into the bullpen by giving him low-stress situations. This should allow him to get more comfortable, and hopefully to where he needs to be to contribute.