Need an impact arm or bat that can give your fantasy team a boost? Whether you're looking for an injury replacement or someone to stash on your bench, the fantasy waiver wire has a plug or long-term fix to pick up today.
Check out the following 10 players -- all sitting on waivers in many leagues, and all ready to help your team in Yahoo Sports Fantasy Baseball, the Official Commissioner Game of MLB. All statistics and ownership percentages are as of Wednesday morning.
Danny Duffy, starter, Royals (44% owned)
Duffy was drafted in virtually every fantasy league, but his rocky start -- he's 1-6 with a 6.88 ERA and a 1.73 WHIP -- has his ownership percentage below 50. Walks and home runs have contributed to his early slump, with his BB/9 rate rising from 2.5 BB/9 in 2017 to 4.4 BB/9 in '18 and his HR/9 rate jumping from 0.8 HR/9 last year to 2.5 HR/9 this year. In fact, he's already allowed more home runs (14) in 51 innings this year than he did in 146 innings (13) last year, as his 17.9 percent HR/FB rate is well above his career rate (9.8 percent). Owners won't find much solace in his 6.44 FIP or 5.35 xFIP, but this is a 29-year-old who entered 2018 having posted a 3.43 ERA with a 3.85 FIP across the previous six years. He's worth an add based on the upside, even if owners don't put him in their lineups until he shows signs of turning things around.
Richard Parker, reliever, Angels (44% owned)
With Keynan Middleton landing on the disabled list last week, Parker has re-emerged as a closing option for the Angels. He notched his second save of the year in his most recent appearance on May 20 and has been trending up lately, with no earned runs in 9 2/3 innings spanning his past nine appearances. Manager Mike Scioscia has yet to commit to a closer (Justin Anderson, Jim Johnson and Cam Bedrosian are also in the mix), but Parker could continue receiving save chances based on his 2.78 ERA, 1.24 WHIP and 10.3 K/9 rate this season.

Vladimir Guerrero Jr., third baseman, Blue Jays (42% owned)
MLB's No. 2 overall prospect hasn't debuted yet, but he's making a case for a promotion by slashing .423/.475/.692 with eight homers and 45 RBIs through his first 40 games at Double-A New Hampshire this year. He's demonstrated strong plate discipline during his time in the Minor Leagues, tallying more walks (126) than strikeouts (114), and can run a bit, too, as evidenced by his 25 steals in 221 games. The 19-year-old will likely be called up at some point this season, if not in the near future, making him a stash candidate for fantasy owners with a bench spot to spare.
Tyler O'Neill, outfielder, Cardinals (38% owned)
O'Neill has been red hot since being recalled from Triple-A Memphis on May 18, hitting safely in all five of his games while batting .500 with three home runs and six RBIs. The 22-year-old rookie showcased elite power in the Minor Leagues, belting 44 home runs with 126 RBIs in 159 games at Triple-A in 2017 and '18. The Cardinals have a crowded outfield with Tommy Pham, Marcell Ozuna and William Fowler, but O'Neill's pop could help him force his way into the lineup, especially if Fowler (.558 OPS) continues to struggle.

Austin Meadows, outfielder, Pirates (26% owned)
Meadows has hit the ground running since debuting on May 18, batting .400 with two home runs, three RBIs and a stolen base in four games. MLB Pipeline's No. 42 overall prospect is expected to play regularly with Starling Marte (right oblique strain) on the disabled list. Meadows slashed .292/.357/.454 in the Minor Leagues while showing power and speed, notching 11 home runs and 27 steals in 141 games at Triple-A Indianapolis from 2016-18. With just one strikeout and an average exit velocity of 93.6 mph in his first 15 MLB plate appearances, the 23-year-old rookie has the potential to be a difference-maker while Marte is on the mend.
Trevor Cahill, starter, A's (24% owned)
Cahill has been excellent in his return to the A's this year, recording a 2.75 ERA with a 0.97 WHIP in 36 innings. Better command has been one of the keys to his early success, with his 2.3 BB/9 rate representing a career best as well as a dramatic improvement from his 4.8 BB/9 rate across 2016-17. And with an 8.8 K/9 rate as well as a 60.4 percent ground-ball rate, the 30-year-old isn't giving batters much of a chance to do major damage against him.

Dustin Pedroia, second baseman, Red Sox (20% owned)
The veteran second baseman is on track to return from the disabled list this weekend after being sidelined all year while recovering from offseason left knee surgery. Pedroia batted .293/.369/.392 with seven homers, 62 RBIs and a 49-to-48 BB/K ratio in 105 games last year, showing he can still hold his own at the plate. With the Red Sox ranking second in MLB in runs scored, Pedroia should get ample opportunities to score and drive in runs when he returns to the lineup.
Willy Adames, shortstop, Rays (11% owned)
Adames didn't take long to make a good first impression, homering off Chris Sale in the second at-bat of his MLB debut vs. the Red Sox on Tuesday. Tampa Bay's No. 2 prospect per MLB Pipeline, Adames was hitting .311/.387/.466 in 40 games at Triple-A Durham this year before being called up. While he's expected to be sent back down when Joey Wendle returns from the paternity list, the 22-year-old Adames could cause the Rays to change their plans by continuing to swing a hot bat.
Matt Harvey, starter, Reds (11% owned)
Harvey has shown signs of turning his season around since joining the Reds, posting a 2.57 ERA with a 0.93 WHIP and 12-to-2 K/BB ratio in three starts with Cincinnati. Since leaving the Mets, his walks are down (from 3.0 BB/9 to 1.3 BB/9), his strikeouts are up (from 6.7 K/9 to 7.7 K/9) and he's allowing home runs less frequently (1.3 HR/9 vs. 2.0 HR/9). His 3.68 FIP is nearly two runs lower than the 5.63 mark he had with New York this year, indicating he may be regaining his effectiveness on the mound.

Johnny Field, outfielder, Rays (3% owned)
Field has flourished since debuting on April 14, slashing .309/.347/.544 with four home runs, eight RBIs and 14 runs over his first 23 games. The 26-year-old rookie batted .271/.330/.444 across all levels in the Minor Leagues with solid power and speed, tallying 17 homers and 15 steals in 184 games at Triple-A Durham from 2016-18. With outfielders Carlos Gomez (right groin strain) and Kevin Kiermaier (right thumb surgery) both on the disabled list, Field should continue seeing steady at-bats in the short run.