MLB Game Preview - Colorado at Milwaukee

Mon Apr 3, 2017 2:10 PM EDT

MILWAUKEE -- Junior Guerra's improbable story adds another unexpected chapter Monday when he throws the Milwaukee Brewers' first pitch of the season against the Colorado Rockies at Miller Park.

The 32-year-old split-finger specialist wasn't on Milwaukee's Opening Day roster a year ago, but you have to go back a little further to fully appreciate the significance of Guerra's start.

A prospect in the New York Mets system, Guerra was suspended for 50 games after testing positive for banned substances in January 2009 and released when that suspension ended.

While pitching in the Venezuelan winter league, Guerra was demoted and spent the next few years pitching in baseball's wilderness, including stops in Italy and an independent league team in Kansas before the Chicago White Sox took a flier on him in 2015.

Guerra reached the majors late that season but was waived at the end of the year. He would ultimately be claimed by the Brewers -- the first official transaction of general manager David Stearns' tenure -- and after he finally got the call back to the majors last April, he was ready to show the baseball world what it had been missing.

Guerra went 9-3 with a 2.81 ERA in 20 starts, stabilizing Milwaukee's rotation and installing himself as a key cog in the Brewers' rebuilding efforts.

"There were times in my long journey I thought I was done. I've got to thank my wife a lot because she kept pushing me to stay it," Guerra said through team interpreter Carlos Brizuela. "Thankfully, she pushed me and thankfully I stayed with it."

Guerra is on an Opening Day roster for the first time in his career, as is his Colorado counterpart, Jon Gray, who started the 2016 season on the disabled list but went on to strike out 185 in 168 innings while going 10-10 with a 4.61 ERA in 19 games.

Over the offseason, he added a curveball to his mid to high-90s fastball and biting slider in the hopes of taking another step in his development.

"I think it's been the difference-maker," Gray told the Denver Post late in spring. "This whole spring, I really haven't thrown much of my slider and I didn't have a great feel for it most of the spring, but the curveball has been a great replacement. And now I know that no matter what, I'm going to have that pitch. That's good, positive energy."

Gray struck out 19 with only four walks in 15 1/3 innings of Cactus League work but was pulled early from his final exhibition start with a sore toe. The injury turned out to be insignificant and Gray will be ready to go Monday afternoon.

I've been thinking about it for a long time," Gray said of the season opener. "Us guys have been talking about it for a long time. We're going to get the ball rolling on what we believe is going to be a really good season. We're really confident in each other, and we know what to expect from each other."

Colorado went 1-5 against the Brewers last year and has lost two of the past three season series with Milwaukee.