MLB Player Props & Bets: Thursday (5/21)
There are only seven MLB games on the schedule today, but there's no shortage of betting options. I'm heading to the prop sheet in this article, where I've narrowed in on four props from Thursday's slate. Let's dive into my top MLB player props for Thursday, May 21st.
Get instant alerts when a line reaches your target via the BettingPros App >>
Thursday’s Top MLB Player Props & Bets
(Odds courtesy of FanDuel Sportsbook unless otherwise stated)
Casey Mize Over 16.5 Outs Recorded (-114)
At first, I was looking to make a play on Casey Mize's under on pitching outs, since the Guardians' offense has been hot. That was until I saw that his line is just 16.5 outs, meaning we only need 5.2 innings from the right-hander to cash this bet. Mize has thrown at least 5.2 innings in five of his seven starts this season.
Mize has cleared the threshold in all three home starts in 2026. He has been electric at Comerica Park, posting a 1.02 ERA and holding opponents to a .177 batting average. Jose Ramirez has gotten to Mize, going 5-for-11 (.455) against him, but the rest of the Guardians' roster is just 6-for-34 (.176).
Mize is in line for another quality start. I'll take his over on 16.5 pitching outs recorded.
Juan Soto Over 1.5 Hits + Runs + RBIs (-130)
New York's Juan Soto has rebounded from his slow start in 2026, and he's crushing the ball right now. Over the last week, the superstar slugger ranks 11th in wOBA (.543), 16th in batting average (.417) and 17th in ISO (.375). He has logged two or more combined hits + runs + RBIs in six straight games, as well as in seven of his last eight outings.
This is also a favorable matchup for Soto, as he's squaring off against Washington's Cade Cavalli. He's 4-for-5 (.800) lifetime against the Nationals right-hander, blasting a home run and a double. Cavalli hasn't been sharp this season, registering a 4.05 ERA and a 1.54 WHIP. Let's ride with Soto to go over this combo prop at a relatively low price.
Matt Olson Under 0.5 Hits (+154 at DraftKings Sportsbook)
Matt Olson is in a bit of a slump, going hitless in three of his last five games. Over the last week, the first baseman is hitting just .190 with 29.2% strikeout rate and a .048 ISO.
I don't anticipate his turning things around against Sandy Alcantara (3.53 ERA), who has limited the Braves star to just 2-for-25 (.080) lifetime. Let's take a shot with this lofty payout to say Olson doesn't record a knock.
Nolan Arenado Over 1.5 Total Bases (+115)
I'll close out the night by playing Nolan Arenado to clear 1.5 total bases. I like this bet at plus-money, especially considering Arenado has eclipsed the number in four of his last six games. Over the last seven days, Arenado ranks 15th in the Majors in wOBA (.505) and is hitting .350.
Arenado will be looking to stay hot against Colorado's Zach Agnos, who brings in a 5.59 ERA and a 1.41 WHIP. The duo just faced off in Denver last week, and Arenado launched a double against the right-hander. He's 1-for-1 (1.000) against him for his career.
Add in that the Rockies' relief staff is still a lousy 20th in ERA (4.36) and 25th in opposing batting average (.255), and we should see Arenado have plenty of quality chances at the plate.