Week 19 Fantasy Baseball Waiver Wire Infielders: Tyler Locklear & Coby Mayo Surge

As the fantasy baseball season enters its final stretch, savvy managers can gain an edge by targeting emerging infield talent. From red-hot catchers like Edgar Quero to power-hitting shortstops like Colson Montgomery, these players are trending up and could be league-winners down the stretch.

Catchers

Edgar Quero, Chicago White Sox

The White Sox have had Quero in their starting lineup four times over their last five games, heading into Friday night. He responded with nine hits over 21 at-bats with four runs, one home run, and four RBIs. Two of his three home runs over 218 at-bats have come over his last 32 at-bats, signaling a more helpful fantasy bat over the final two months of the season. In 2024, between AA and AAA, he hit .280 over 350 at-bats with 41 runs, 16 RBIs, and 70 RBIs.

ANOTHER ONE BY EDGAR QUERO ‼️ pic.twitter.com/cNBDamjAEj
— White Sox on CHSN (@CHSN_WhiteSox) July 30, 2025

Kyle Higashioka, Texas Rangers

After sitting out five games with a hamstring issue, Higashioka has been the Rangers’ starting lineup for their last three games (5-for-11 with four runs, two home runs, and two RBIs). He hit .379 in July over 58 at-bats with eight runs, five home runs, 11 RBIs, and three stolen bases, giving him C2 value in 12- and 15-team formats.

First Basemen

Tyler Locklear, Arizona Diamondbacks

Locklear struggled at AAA in 2024 (.260/53/8/41/5 over 265 at-bats) in the Mariners’ system while hitting his stride this year after repeating the same level (.316 over 373 at-bats with 70 runs, 19 home runs, 82 RBIs, and 17 steals). Locklear has been at his best in July (.422 over 83 at-bats with nine runs, 34 RBIs, and six stolen bases). His success at the plate over the weekend will drive his value and interest in fantasy leagues.

Prospects Tyler Locklear and Jordan Lawlar will get their shot with Eugenio Suarez and Josh Naylor off the Diamondbacks and now with the Mariners.

“We’re gonna work really hard with (Locklear) at first base, but as a young first baseman that we feel like has the power and the… pic.twitter.com/7bl1Z451XZ
— Arizona Sports (@AZSports) August 1, 2025

Ryan Mountcastle, Baltimore Orioles

As of midday on Friday after the trade deadline, the Orioles haven’t called up Mountcastle, but he is worthy of a follow to see if they slide him back into their starting lineup. Over five rehab games at AAA, he has five hits over 19 at-bats with three runs, two home runs, and six RBIs. His bat dug a fantasy hole over his first 187 at-bats with the Orioles (.246/19/2/15/1).

Second Basemen

Brooks Lee, Minnesota Twins

The fire sale in Minnesota ensures that Lee will be in the starting lineup most days for the Twins over the final two months of the season. He put two balls in the seats on Tuesday night with five RBIs, putting him on the radar in shallow leagues at second base. Over his past 23 games, his bat has been trending downward (.157/4/2/11 over 70 at-bats), painting him a fantasy liability. When at his best in the minors (AA and AAA) in 2024, Lee hit .275 with 83 runs, 16 home runs, 84 RBI, and seven steals over 501 at-bats.

Cole Young, Seattle Mariners

I sense a productive run coming from Young, helped by the Mariners extending their starting lineup at the trade deadline. Over his last 15 games, he went 13-for-46 (.283) with seven runs, three home runs, and seven RBIs. For some reason, Seattle has yet to give him the green light on the base paths (no attempts) after showing strength in this area in 2023 and 2024 in the minors (44-for-65 in stolen bases).

Third Basemen

Coby Mayo, Baltimore Orioles

Heading into the weekend, Mayo sits atop the Orioles’ depth chart at first base while also having a third base qualification. He has seven hits over his last 20 at-bats with five runs, two home runs, and five RBIs. More importantly, he had five walks and only two strikeouts. Mayo is getting more comfortable at the plate in the majors, making him an upside flier in deep formats.

Ke’Bryan Hayes, Cincinnati Reds

The Reds started Hayes last in their batting order after acquiring him, which won’t excite the fantasy market. He gets a bump in fantasy value by home ballpark and overall scoring potential by Cincinnati’s lineup. Hayes hit a three-run home run in his first game with his new team, but his bat has been quiet over his last 11 contests (10-for-43 with five runs, one home run, and eight RBIs). At best, a one-week flier in deep leagues to see if Hayes can hit his way to a higher slot in the batting order.

Ke'Bryan's first home run as a Red@KeBryanHayes pic.twitter.com/UibAuO0V7N
— Cincinnati Reds (@Reds) August 1, 2025

Shortstops

Jeremiah Jackson, Baltimore Orioles

The Orioles have to be ecstatic with the development of Jackson’s bat over his last 33 games (.400/24/8/18/9 over 135 at-bats) while taking nine walks and striking out 17 times. His bat was much weaker earlier this season at AA (.254 over 177 at-bats with 18 runs, four home runs, 19 RBIs, and two stolen bases). Baltimore called Jackson up on Friday, but he falls into only the watch category until his bat talks him into a starting job.

Colson Montgomery, Chicago White Sox

Montgomery’s power emerged over the past two weeks. He has nine hits over his last 36 at-bats with seven runs, five home runs, and 13 RBIs while taking no walks and striking out six times. Over five seasons in the minors, he hit .246 with 221 runs, 48 home runs, 186 RBIs, and 15 steals over 1,385 at-bats.