Tampa Bay Rays outfield prospect Chandler Simpson is batting leadoff in his MLB debut on Saturday afternoon against the New York Yankees. Simpson will cover center field and face New York right-hander Carlos Carrasco. The Rays promoted Simpson from Triple-A Durham before Friday's contest. Simpson carries elite speed upside. Last summer in the minor leagues, the 24-year-old swiped an impressive 104 bags across 110 contests between High-A and Double-A. He made his Triple-A debut this season and needed only 17 games to prove he was ready for the majors. In his brief stint with the Durham Bulls, Simpson posted a .301/.325/.329 slash line with eight stolen bases. Simpson should be viewed as a must-start option in category formats given his elite speed. However, he does not carry any power upside.

Detroit Tigers right-handed pitcher John Brebbia (triceps) was placed on the 15-day injured list due to a right triceps strain. In a corresponding move, the Tigers promoted left-handed pitcher Bailey Horn from Triple-A Toledo. Brebbia has enjoyed a strong start to the campaign. Pitching out of the bullpen, the right-hander has logged nine innings to the tune of a 1.00 ERA and a 0.89 WHIP. He has held a 9:5 K:BB and allowed just three total hits. The Tigers have typically deployed Brebbia in the eighth and ninth innings in high-leverage situations. With Brebbia sidelined, fantasy managers should expect Tommy Kahnle to continue to operate as the go-to option for saves while Will Vest and Tyler Holton operate as the setup options.

Seattle Mariners outfielder Julio Rodriguez will get his first day off the season on Saturday afternoon when the Mariners continue a series against the Toronto Blue Jays. Rodriguez has gone just 1-for-16 over his last four contests with a 20.0 percent strikeout rate. Fantasy managers should expect the star outfielder to return to the starting nine on Sunday. Through the first 20 games of the campaign, the former top prospect has held an underwhelming .179/.304/.359 slash line with three home runs. However, a look under the hood suggests Rodriguez should see significant positive regression throughout the season. He has generated a strong .352 xwOBA with a 93.7 mph average exit velocity and a 75.3 mph bat speed, which are all well above the average marks. With Rodriguez sitting out, Luke Raley will cover center field, and Miles Mastrobuoni will enter the starting nine. The Mariners are a viable stack in DFS facing Toronto right-hander Jose Berrios.

The Miami Marlins have promoted left-handed pitcher Pat Monteverde to the major league roster prior to Saturday's contest against the Philadelphia Phillies. In a corresponding move, the Marlins optioned right-handed pitcher George Soriano to Triple-A Jacksonville. Monteverde has yet to appear in an MLB contest. Through the start of the Triple-A regular season, Monteverde has logged nine 1/3 innings to the tune of a 4.82 ERA and a strong 1.07 WHIP. He has struck out six batters and served up four walks. Last season, the southpaw spent most of the season with Jacksonville and held a high 5.66 ERA with a 1.51 WHIP. Soriano has posted a 6.94 ERA through his first 10 innings of the season with Miami. Fantasy managers should expect Monteverde to operate in a low-leverage role in the Miami bullpen.

The Kansas City Royals have optioned outfielder MJ Melendez to Triple-A Omaha. This transaction opened a spot on the roster for Mark Canha (hip), who was activated off the injured list in a corresponding move. Melendez has had a rough start to the campaign and will look to find his footing in the minor leagues. Through the first 16 contests, Melendez has posted a .085/.173/.170 slash line with just one double and one home run. He has held a low 5.8 percent walk rate and a high 38.5 percent strikeout rate, which placed him in the first percentile among qualified hitters. In addition, Melendez generated a weak .224 xwOBA. With Melendez heading to Triple-A, fantasy managers should expect Jonathan India, Mark Canha, and Drew Waters to share time in left field.