"He came through very well," Maddon said, although Kazmir reportedly struggled with the early game time.
The southpaw tossed four and 2/3 innings in the Class A Vero Beach Devil Rays' 4-3 loss to the Palm Beach Cardinals. Kazmir totaled 64 pitches and will have a final start at Triple-A Durham on Monday night before his much-anticipated debut.
The Rays ace left an intrasquad game on Feb. 25 with a left elbow strain and has been on the disabled list since the end of March.
The question remains about which day Kazmir will start simply because Maddon does not want the rest of the rotation to get to much rest between outings. With Monday's off-day, the club has done surprisingly little shuffling, and it may have even helped No. 3 starter Matt Garza, who is expected to come off the DL and start Friday.
Kazmir led the American League in strikeouts last season and will join a Rays staff that is among the best in the Majors.
Through the team's first 20 games, the bullpen has given up only 18 earned runs in 62 1/3 innings of work, limiting opponents to a .218 average. The team's relief ERA, 2.61, is tops in the Major Leagues and is a nearly 3 1/2 runs lower than last season.
In 17 games vs. the Red Sox, Kazmir is 6-5, with a 2.66 ERA.
Brittany Ghiroli is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.