Fantasy Baseball Waiver Wire Top Pickups: Week of May 4th

Welcome to May. The month when you drop that draft pick more likely out of frustration than good process. Samples have grown, and we have seen a couple of flashes in the pan come and go, while a few have actually stuck.

Injuries are beginning to pile up, making the waiver wire an ever-changing list. Luckily, there are still a number of impact players that should make sense for your league, big or small. Today, I’m going to highlight a couple of options to pick up saves, a catcher who’s always hitting, and a young bat who is still somehow underrated.

Stats as of first pitch on May 3. Ownership percentages via ESPN.

Jack Perkins – RP – Athletics (8%)

2026 Stats: 13.1 IP, 3 SV, 2.70 ERA, 1.72 FIP, 11.48 K/9, 2.03 BB/9

Jack Perkins has been one of my personal favorite underrated arms for a couple of years now. The Athletics did not give him the ninth to start the season, but he’s found his way there now and is starting to get more and more opportunities.

A 33% whiff rate or better on his secondaries with a very high 25% whiff rate on his four-seamer has produced a 31% strikeout rate to start the season. Pair that with a much improved 5.5% walk rate, and you have the makings of a valuable fantasy closer. Scoop him up as the A’s continue to win more games and his value rises.

Nick Martinez – SP – Tampa Bay Rays (25.4%)

2026 Stats: 6 GS, 1.70 ERA, 3.64 FIP, 5.84 K/9, 2.19 BB/9

Nick Martinez is a bit of a risky pick up, but the numbers are too good to pass on, and his track record is solid enough to think what we are seeing will continue. He’s not going to get you many strikeouts, six being his season high, but he avoids hard contact and walks.

It’s not a sexy pick-up or one that carries much upside. However, you might need a guy for a couple of starts while your team gets healthy, and Martinez fits that need well. Trust in the Rays and their eye for pitching.

Kyle Finnegan – RP – Detroit Tigers (4.2%)

2026 Stats: 15.2 IP, 0.57 ERA, 4.36 FIP, 6.89 K/9, 5.74 BB/9

Kyle Finnegan has been one of the more consistent relief pitchers for the past five or six years. He’s not flashy but is productive. His strikeout numbers are a bit wonky due to an odd stretch earlier in the season, but he has recorded a strikeout in each of his last six outings, including four in one outing.

Kenley Jansen has been a disappointment, and Will Vest just hit the IL. Finnegan has started to see the ninth more, and if he establishes himself as the true closer in Detroit, which I think is very possible, his value is about to take off.

Iván Herrera – C – St. Louis Cardinals (36.5%)

2026 Stats: .256/.421/.427, 4 H, 1 SB, 144 wRC+

The Cardinals have been one of the pleasant surprises this season, and a big reason why is Iván Herrera. This guy can just flat out hit. He has posted a 128 or better wRC+ in three straight seasons now, and the power is good enough to reach 20 home runs.

Injuries have been a problem in the past, which could have hurt his preseason hype. Yet, he doesn’t strike out often, can swipe a good amount of bags for a catcher, and hits the ball hard enough to reasonably think more power is possible.

Colson Montgomery – SS – Chicago White Sox (23.7%)

2026 Stats: .231/.338/.504, 9 HR, 1 SB, 130 wRC+

Montgomery hit 21 home runs in 71 games as a rookie last season. This year, he has already hit nine home runs across 33 games, making him a legit power hitter. He’s chasing outside of the zone less than last season, which has helped him drop his strikeout rate by a bit.

Strikeouts are still the problem and will likely continue to be. He’s at a 27% K% right now, but you would hope his improvements continue with more time on task. Any improvement will be massive due to how often he leaves the yard on contact, so pick up this young power hitter now and hope he can slice his K% to around 25% and give your team power.