That's the bad.
The good: Walker threw 61 pitches (38 strikes), then 14 more in the bullpen after being taken out. He showed no signs of ailing from the shoulder injury that's kept him sidelined the last six weeks.
It left him with a positive outlook after the Rainiers lost, 5-3, to the visiting Salt Lake Bees.
"The start really wasn't about the numbers," Walker said. "It was pretty much just about how I feel. I felt good."
After all, it wasn't Walker's first time in this position. On April 15, the 6-foot-4, 220-pound right-hander was set to pitch for the Rainiers in what some thought would be his last start before being recalled to the Major Leagues after spending most of Spring Training rehabbing from inflammation in the bursa sac of his throwing shoulder.
But the right-hander complained of shoulder stiffness a few hours prior to first pitch and was subsequently scratched, then placed on the 15-day disabled list.
"The setback definitely [stunk], but I stayed positive and have been working my butt off to get back out there," Walker said. "Making this rehab start was huge."
Walker isn't sure when he might rejoin the Mariners' rotation, but said he is on a "five-day" schedule. He'll do light throwing tomorrow, then pitch a bullpen session Friday. Earlier this week, the Mariners placed left-hander James Paxton on the 15-day DL after he developed shoulder inflammation while rehabbing from a back strain he sustained April 8.
"I feel for Paxton," Walker said. "I went through the same thing. I've just got to focus on what I have to do, and what I have to do to get ready, and focus on making sure I'm healthy."
On Wednesday, his first inning began with second baseman Ty Kelly committing a throwing error on a weak-hit ground ball. Walker followed by retiring the next three hitters to end the inning. In the second, he yielded a leadoff single, then retired three in a row. He showed a fastball that consistently stayed in the low 90's, but was clocked at 95 mph at least once on a breezy night.
He was dinged in the third after allowing a leadoff single, then inducing two fly-ball outs.
Bees' No. 3 hitter Roberto Lopez singled to put runners on first and second, then cleanup man Efren Navarro followed with a three-run homer down the right-field line. Salt Lake third baseman Luis Jimenez added a solo shot to give the Bees a 4-2 lead before Walker fanned designated hitter Shawn O'Malley to end the inning.
"I think he got tired a little bit, he got the ball up a little bit a couple times, but that's all understandable," said Rainiers manager Roy Howell.
"The ball was up. I wasn't finishing my pitches. I felt like my stuff was pretty good -- just a couple mistakes here and there," he said.
Walker said he threw mostly fastball and cutters and that his curveball felt "all right," though one pitch gave him trouble.
"I didn't throw as many changeups as I'd like to, but it wasn't really feeling too good in the bullpen," he said.
Walker has made a mechanical adjustment where uses his legs more and finishes through pitches, with the hope it takes stress off his shoulder. He's thrown two simulated games on his latest rehab stint, but the adjustment is still a work in progress.
"It's still new, I'm still trying to get used to it. I'm not used to finishing violently, I guess, getting out there," he said. "It's a lot different from the bullpen to an actual game so I just got try to translate it to the game and go from there."