Sizemore, 32, appeared in 39 games with the Phillies this season before he was released on June 1. He is a three-time All-Star with two Gold Gloves and a Silver Slugger from his time with the Indians.
The plan is for Sizemore to report to Class A Advanced Charlotte to "get his timing back" since he's been off "10 to 12 days," according to Rays manager Kevin Cash.
"Given the situation, obviously we can use another left-handed bat with some of the guys that we have down," Cash said. " ... We'll let him get his feet wet, get some timing back and kind of evaluate. I think it's a pretty open situation where he's going to communicate well with us and we're going to communicate well with him and go from there after he gets his timing down."
Sizemore's signing sounded more like a move to get a player they want to use than merely a move to add to the organization's depth. Cash suggested that he could be up with the club in the near future.
"If he's good to go, and feels well, he's healthy, we can use him," Cash said. "But I don't think there is a timetable set. We're just going to kind of let it play out and see how he feels."
This season, he hit .245 with five doubles and six RBIs.
Over a 10-year career with the Indians, Phillies and Red Sox, Sizemore is a .265 career hitter with 20-plus stolen bases in four seasons.
Wilson, who was designated for assignment last Thursday, cleared waivers and accepted an outright assignment to Triple-A Durham. He will join the Bulls when they return home on Thursday.
In 24 games with the Rays this season -- 16 starts at catcher -- Wilson batted .145 with four RBIs, but the team posted an ERA of 2.85 when he was behind the plate, which would be the eighth lowest catcher's ERA in the league if he qualified.
"He's going to go to Durham, we're all on boad with that," Cash said. "Gives us more depth. We all understand the catching sutation alone is one foul ball, one nick here and there, and you can never have enought depth. We've shown that first hand this year at other positions. Maybe Bobby gets down there, has some regular at-bats. We know he can help us out in a pinch up here."