The 28-year-old outfielder will start in right field in place of the injured Jose Bautista and hit seventh in the batting order against Rays right-hander Erasmo Ramirez.
Saunders suffered a knee injury in spring training after a freak accident with a sprinkler head that required surgery. At first, the Blue Jays feared he would be lost to the team until the all-star break in July.
In December, Toronto general manager Alex Anthopoulos jumped at the chance to acquire Saunders with the prospect of re-signing left-fielder Melky Cabrera fading, dealing left-hander J.A. Happ to the Seattle Mariners.
Saunders, who played for Canada at the 2013 World Baseball Classic, hadn't reached his potential in parts of five seasons with Seattle. A glimpse of that potential was displayed in 2012 when Saunders hit 19 home runs and stole 21 bases in a career-high 139 games.
However, since the start of that season, he has a .248 batting average and 39 homers in 349 contests.
Reserve infielder/outfielder Steve Tolleson was designated for assignment on Friday when Saunders was activated from the disabled list.
Toronto has 10 days to either trade, release or waive Tolleson, who was hitting .200 in 15 at-bats this season. Last season, he slashed .253/.308/.371 in 189 plate appearances.
The Blue Jays don't top the list of preferred teams against which many pitchers would elect to make a spot start.
Given his start against them 10 days ago, Ramirez would probably agree.
Potent Jays offence
Nevertheless, he'll be called upon to try to continue what's outside of that one game been early season dominance against the typically high-scoring Blue Jays.
The Rays (9-8) have 10 players on the disabled list, including four starting pitchers. Ramirez is one of seven starters they've used, and after Matt Andriese earned a three-inning save in Friday's 12-3 win in the opener of a three-game home set, Ramirez (0-1, 21.32 earned-run average) will get the ball with hopes of improving on considerable early struggles.
In his only start, the right-hander allowed eight earned runs and nine hits with three walks in 3 1-3 innings of a 12-7 loss in Toronto (9-8) on April 15. He made it through a clean relief inning four days later, but he's walked six in 6 1/3 innings and is serving up a .455 opponent batting average.
In four career games against the Blue Jays, Ramirez is 1-1 with an 8.31 ERA.
The Rays took three of four in that series from April 13-16 and have won six of eight between the American League East clubs since being swept at home from Sept. 2-4. In those eight games, the Blue Jays are batting .195, despite a 14-hit showing in Ramirez's start.
The Rays have won three straight and will have right-fielder Steven Souza Jr. back in the lineup Saturday after being rested Friday.
Toronto, which leads the majors with 97 runs, saw a three-game winning streak come to an end in its third straight game without Bautista because of a sore shoulder.
Manager John Gibbons said Bautista, who is 2-for-3 with a home run against Ramirez, won't go on the disabled list and is likely to DH this weekend before returning to the outfield.
Starter Daniel Norris is also seeking improvement. Norris (1-1, 6.08) is still trying to make it through six innings in a big league start, and he wasn't even close his last time out. The left-hander allowed five runs and six hits in 2 2-3 innings of Sunday's 5-2 loss to Atlanta.
"I'm going through a little bit of a dead-arm phase, so it's really tough for me to feel that late life on everything that I was used to in spring training," Norris said. "… I can definitely get through it, dead arm is just something where you feel 100 percent fine, it just doesn't come out like it usually does. Even if I throw one that says 93 or 94 mph, it just doesn't have the same life on it. I can't really command it the way I'm used to."
Probably his best start came April 14 at home against the Rays as Norris surrendered two runs and two hits with three walks in five innings.