Those numbers seem to be all manager Joe Girardi needed to know.
"With as many left-handed hitters as they have, we thought adding another left-hander would be beneficial," he said.
Olson made his debut on Friday, entering in relief of Kirby Yates with one out in the seventh inning. The Mariners pinch-hit the righty-swinging Franklin Gutierrez for the left-handed-hitting Seth Smith. Gutierrez hit a sac fly to right field to give Seattle a 5-1 lead. Olson then got the dangerous left-handed-hitting Robinson Cano to fly out to Starlin Castro to end a nine-pitch at-bat and the inning.
To Olson, who pitched for the Mariners last year, a chance to face his former team isn't as special as some may assume.
"It'll be different, just seeing guys I played with last year a little bit," Olson said. "But again, like I said, I'm just happy to be here."
Olson struggled to keep runners off the basepaths in his big league appearances in 2015. The left-hander pitched in 11 games for the Mariners last season, logging a 1-1 record and a 5.40 ERA in 13 1/3 innings pitched. Olson walked 10 batters and allowed 18 hits in those appearances, leading to a 2.10 WHIP.
As for Cessa, the young righty made one appearance this season, allowing one run and two hits while striking out two in two innings against the Tigers or April 8. The run came via a home run by slugger Miguel Cabrera.
The Yankees aren't done with Cessa, however. Girardi outlined the plan he already has in mind for what Cessa needs to do before returning to the bigs.
"I thought Cessa did a good job while he was here," Girardi said. "He'll obviously go down and he'll get built up. I think his first outing will probably be in relief three innings, but we will continue to build him up [as a starter]."
Nick Suss is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.