"We believe he can fill this role really effectively," Boone said. "It's important for him to come out and make pitches and pitch well. We really like where he's at and the way he's throwing the ball right now."
Cessa, 26, scattered four hits without a walk in the outing. Though most of the spots in the Yankees' elite bullpen are spoken for, there is conceivably at least one vacancy behind Dellin Betances, Zack Britton, Aroldis Chapman, Jonathan Holder and Adam Ottavino.
Boone will need a pitcher capable of providing distance or a spot start, and Cessa is competing against Domingo German and Jonathan Loaisiga to win that opportunity. Cessa's contract status could work in his favor, as he is out of Minor League options, unlike German and Loaisiga.
"I try to not think too much about that," Cessa said. "The last two years, I put too much pressure on myself. I'm staying focused on my work, working hard every day, and when I have the opportunity to pitch, I try to do my best."
Cessa compiled a 5.24 ERA in 16 big league appearances last season, spanning 44 2/3 innings, and said that pitching coach Larry Rothschild has advised him to work on his fastball command. Cessa did that during the offseason and has continued this spring.
"Even though he throws hard, he gets in trouble with his fastball when he misses with it," Boone said. "I think that's what has gotten him in trouble when he's struggled at times. We've also seen him incredibly dynamic, and when he gets it rolling, his breaking ball really plays, and the fastball when he can command it. I think he's going to play a big role for us this year."
Tommy Kahnle impressed the Yankees' coaches with a scoreless inning in Friday's 2-2 tie against the Orioles, striking out each of the three batters he faced. Boone said that Kahnle's velocity was clocked between 95 and 97 mph; according to Statcast, the right-hander averaged 95.1 mph last season, a drop from the 97.8 mph he averaged in 2017.
"That's the best I've seen him throw since I've been here," Boone said. "I thought he didn't have to work to generate the velocity. The life in the zone was really good. He executed some changeups, threw a good slider in there last night. The way the ball is coming out for him, he really feels good about it, and he should. That was exciting to see."
Kahnle reported to camp trimmer, having made changes to his diet regimen, including ending an energy drink habit. Kahnle recently told The Athletic that he was drinking as many as five of the caffeinated beverages per day, but he has cut that to a single cup of coffee.
"I think even though he was bigger last year, he was strong," Boone said. "There's no question we like where his body is now as far as being a little lighter, but I don't think he was ever quite right last year. The way that his arm is working this year, the way his mechanics are, to me, it's working much more efficiently."
• Shortstop Troy Tulowitzki had a mixed day in the field on Saturday, losing a popup that fell for a run-scoring double, but he also dazzled by charging a second-inning Erik Gonzalez chopper and firing across his body for the out.
"We were all taken aback by that play," Boone said. "You can tell he feels very much at home out there. He's very instinctual out there."
• Left-hander Phillip Diehl, a non-roster invitee, was struck in the left side by Jason Martin's eighth-inning liner. Boone said that Diehl was smiling in the dugout after the comebacker, calling the 24-year-old prospect "fearless."
"I think he lulls you to sleep a little bit," Boone said. "He looks young. He looks like a little kid out there, but don't be fooled. He can really pitch. The breaking ball is real, he throws strikes. The fastball is low-90s, but it has characteristics to it. It plays up a little bit."
The Yankees will play a pair of split-squad games on Sunday afternoon, hosting the Tigers in Tampa, Fla. and visiting the Blue Jays in Dunedin, Fla. Masahiro Tanaka will start the home game, opposite Detroit's Daniel Norris. German starts the road game against Toronto's Matt Shoemaker. Both games are set to start at 1:05 p.m. ET.