Harvey suffered from thoracic outlet syndrome last year and had not pitched in a game since undergoing surgery to remove a rib in July.
The St. Louis Cardinals scored four runs against Harvey in 1 2/3 innings Sunday in a spring training game at First Data Field in Port St. Lucie, Fla.
Even though he struggled with his fastball command and decreased velocity, Harvey was pleased.
"Obviously it's been eight months since I played against another team. The biggest thing was going out there and trying, I guess get my mechanics back against another team," Harvey told reporters after his outing. "Today was kind of the first step getting my feet wet in game action and I felt it went pretty well."
Harvey allowed a three-run homer and was pulled after getting two outs in the second inning. He struck out three and threw 39 pitches, topping out at 94 mph with his fastball.
"I think this year, I am taking things a little bit slower, realizing I want to get into the fifth or sixth inning before I really start ramping it up," said Harvey, who turns 28 on March 27. "It's still obviously the beginning of March, I realize there is time for the velo to pick up.
"I threw some good ones (fastballs), some bad ones. Obviously I got behind the count a couple times. ... Overall I was happy with some of the pitches I made. I was happy with some of the weak ground balls. You can't get those every time, but overall I am happy with the way I felt and the way the ball was coming out."
In his second season back from Tommy John surgery in 2016 before being shut down, Harvey went 4-10 with a 4.86 ERA in 17 starts. Overall for his career, Harvey is 29-28 with a 2.94 ERA in 82 starts.