MESA, Ariz. -- Jake Arrieta has spent the past few weeks focusing on his delivery behind the scenes at Cubs camp. He has thrown bullpen sessions and live batting practice, getting feedback from his teammates, coaches and one of his former catchers, manager David Ross.

Now, it is almost time for Arrieta's Cubs debut -- again. The next step for the veteran starter is a Cactus League start on Sunday against the D-backs at Salt River Fields. It will be Arrieta's first start for the Cubs since Game 4 of the 2017 National League Championship Series against the Dodgers.

"I think he's excited to get back on the bump and show what he can do," Ross said on Friday. "And continue to get back to who he thinks he can be, and who we think he can be."

Arrieta -- back with the Cubs on a one-year contract with a mutual option for 2022 -- spent the past three years with the Phillies, and dealt with an assortment of injury issues. After a decent showing in 2018 (3.96 ERA in 172 2/3 innings), the right-hander logged a 4.75 ERA over 180 innings over the '19-20 seasons combined.

With Arrieta feeling healthy and back in front of the Cubs' collective eyes, he has been working on getting his delivery back closer to how it looked in his first Chicago tenure. Ross has played a role in that, taking a more active and vocal approach during Arrieta's mound workouts.

"Identifying where maybe some things could've gotten off for him," Ross said, "has been a good process for him. I think some of the fixes are going to take a little while, right? You've got to get back to being able to compete and still not falling into patterns of bad habits."

Cubs pitching coach Tommy Hottovy echoed that assessment, noting that Arrieta's adjustments will be an ongoing project leading up to Opening Day.

"With Jake," Hottovy said, "we really wanted to make an emphasis on creating the right movement mechanically right now instead of going out and trying to get results, which is why he threw that live BP the other day. We really wanted to focus on the things we're trying to accomplish, knowing that down the road it's going to pay off.

"It's going to take time, because he's battled some injuries over the last few years and, again, bad habits form when you're pitching trying not to feel pain. So, now he feels good, it's kind of retraining a lot of those movement patterns."

Worth noting

• Center fielder Jake Marisnick is currently working back from a mild calf issue, according to Ross. The manager noted that Marisnick, who had setbacks with both hamstrings last year with the Mets, was due to test his legs with some baserunning either Friday or Saturday.

"We're just trying to take it slow," Ross said. " I think the hamstring that popped up in New York was something that he ignored and kept pushing it and it got pretty bad. So, he wanted, and we want, to make sure he's 100 percent when he steps out there."

• Ross noted that Triple-A Iowa manager Marty Pevey has taken the lead in working with Cubs pitchers on bunting and hitting drills. With no designated hitter in the plans for the NL in 2021, pitchers are getting back up to speed in the batter's box.

"They're all four-hole hitters in their mind if you ask them," Ross quipped. "They can't wait to hit and get some bunting. We're definitely on top of that."

• Outfielder Michael Hermosillo, who is in camp as a non-roster invitee, launched a home run in each of Wednesday and Thursday's games for the Cubs. So far, Ross has been impressed with the outfielder's decision-making in the batter's box.

"Quick hands. Good swing decisions," Ross said. "And some real thump. It's nice to watch him go get the ball in left. And I'll try to get him some looks in center here soon."

Quotable

"He put in a ton of work, really, on every aspect of his game. Talking to our strength and conditioning guys and talking to our hitting department, and talking to him, it really feels like he just put in work in every area." -- Ross, on Nico Hoerner

Up next

Right-hander Shelby Miller is scheduled to start for the Cubs on Saturday, when Chicago takes on the Brewers at 2:10 p.m. CT in Maryvale, Ariz. Miller is in camp as a non-roster invitee, competing for a spot on Chicago's staff as a starter or reliever.