The 27-year-old had his contract purchased from Triple-A Rochester on Thursday after posting a 3-1 record and 2.70 ERA in six starts for the Red Wings.
"Obviously, I was excited," said Walters of receiving the news from Gene Glynn, the Triple-A manager. "He just kind of told me I was going up and pitching on Saturday, so make the most out of the opportunity."
Walters owns a 7.24 career ERA in 20 games with the Cardinals and Blue Jays, whom he pitched one inning for in 2011. He was part of a three-team, 11-player deal at last season's Trade Deadline that sent him from St. Louis to Toronto. He elected for free agency in the offseason and signed a Minor League deal with Minnesota.
Saturday marks the sixth start of his Major League career and although it's unknown if it will be an extended stay, an impressive outing could certainly sway manager Ron Gardenhire. The Twins have compiled the worst ERA in the Majors and allowed the second-most runs (177).
For the Blue Jays, rookie Drew Hutchison will take the ball. Hutchison is 1-1 with a 6.65 ERA in four starts since making his Major League debut on April 21.
Hutchison suffered the first loss of his career to the Angels in his last outing. The 21-year-old right-hander went 5 1/3 innings, allowing four runs on eight hits while striking out six. He also served up Albert Pujols' first home run of the season.
"It was pretty effective today other than the one I hung [to Pujols]," Hutchison said after the game. "I was trying to bounce it in the dirt and I didn't execute and when you don't execute your pitches, things like that happen."
Although Hutchison has been limited -- making two starts in which his pitch count was in the 80s -- he's yet to string together a quality start this season. He'll look to correct that against the team with the worst record in the Majors.
Twins: May not kind to Mauer thus far
• Joe Mauer's batting average has dropped to .274 this season and the former American League MVP is hitting .152 (5-for-33) in May.
• Gardenhire said Friday that Justin Morneau, who is on the disabled list with a sore left wrist, could start swinging the bat this weekend.
"He's supposed to be [swinging] [Saturday] or if he's not feeling OK, we could back it up a day," Gardenhire said. "The pace, I don't know if we have a formula here. We're going to let him tell us when he'll be ready."
Blue Jays: Bautista blasts Twins pitching
• Jose Bautista hit seven home runs against the Twins in 2011 -- his most against any team. He hit another two Friday night for his first multi-home run game of the season, as he tries to break out of a 7-for-35 (.200) slump in May.
• The Blue Jays signed Vladimir Guerrero to a Minor League contract on Thursday. However, Blue Jays general manager Alex Anthopoulos said there are no guarantees he'll make the Blue Jays' 25-man roster.
"This isn't someone right now that we're prepared to say is going to be up in Toronto," Anthopoulos said. "I have no idea how he's going to look, how's he going to perform, how he's going to play. ... Certainly, there's the upside that he could play very well and be a factor for us."
• The Blue Jays won the season series against the Twins, 5-1, last season. They outscored the Twins 44-14.