And now the bushy-bearded Arkansas native finds himself one of eight remaining right-handed relievers in camp, a non-roster invitee who rolled through five near-perfect Cactus League outings before allowing two hits and two runs in two-thirds of an inning in his most recent outing against the D-backs on Saturday.
"Blake wasn't quite as sharp last time out, but before that he had a nice little run going," manager Scott Servais said. "He commands the fastball pretty well. The breaking ball, he's got a little split-finger, which is a little bit of a separator. Some of the guys don't have that pitch.
"He was down a lot last year. He was not healthy most of the year, so we've kind of taken it easy on how much we've used him and how much rest he's gotten between his outings. Last time we brought him back one day sooner and he wasn't quite as sharp, but he has had a good spring. He's opened some eyes."
Parker says he's hitting his stride now after pitching just three games with the Cubs' Triple-A Iowa club last year before undergoing surgery to remove loose particles in his throwing elbow. And the 6-foot-3, 225-pounder could be a nice rebound candidate of his own, having posted a 2.72 ERA in 49 outings with 55 strikeouts in 46 1/3 innings with the Cubs in 2013.
"I feel like I did before I had the surgery," Parker said. "There are still a lot of adjustments to make, but I'm excited to see what this season holds."
Parker had surgery in mid-June, began throwing again in late August and pitched a handful of games with Mexicali in the Mexican Winter League to test things out. He feels he's still got a couple of more mph in his fastball, once he irons out some lower-body mechanics, but he's thrilled his arm feels sound and the Mariners have given him an opportunity to compete.
"This is a great situation," he said. "I love this team. I love the staff. They're new themselves, so it's nice to not come into a situation where I'm the outsider looking in. That feels good. I'm excited, whatever they decide. That somebody believes in me and that the work I'm doing is going to be able to bring me back to where I was before, that's big to me."
The once-crowded Mariners clubhouse has grown considerably thinner in recent days, as the original 60 players in camp are now down to 40. Parker knows it's a tough road to the final 25-man roster. He pitched 74 games over three seasons for the Cubs from 2012-14, but never made the Opening Day roster.
"The anxiety of coming to the field every day and not knowing the future, that's part of it," he said. "I guess that's the exciting part of it, too. There wouldn't be highs without the lows, and we've all been through it before, so it's part of it. But I'm just excited for what this season holds, wherever it may end up."