A new week of the 2026 fantasy baseball season kicks off on April 20, one that also comes with new pitchers to target. It was a grand week for Spencer Arrighetti & Mitch Keller, both of whom had standout starts over the past seven. And, both make our Week 4 pitcher waiver wire target list for 2026.
Best Week 4 pitchers to target
- SP Spencer Arrighetti (Astros)
- SP Mitch Keller (Pirates)
- SP Michael McGreevy (Cardinals)
- RP Caleb Thielbar (Cubs)
- SP Justin Wrobleski (Dodgers)
We’ll start with the likely two-start starter options for the week.
Spencer Arrighetti had a grand 2026 MLB debut, with 10 strikeouts over six innings. That was against the Rockies on April 15. In it, he netted a swing-and-miss in over 40% of swings induced.
Arrighetti was one of our underrated favorites from last season. However, injuries limited him to seven starts in 2025, and he wasn’t consistent at all in those outings. But so far, all good from Arrighetti, who struck out 20 over 14 innings with Triple-A Sugar Land before the move to Space City.
He’ll get the Guardians on the 20th.
Michael McGreevy, one of baseball’s preeminent strike throwers, will face the Marlins on the 20th. As of April 19, McGreevy’s 1.3 BB/9 was fourth-best among starters with 15+ IP in 2026. That, along with a good defense, has helped keep him to a sub-3.00 ERA and sub-1.00 WHIP despite an expected ERA over 7.00 and one of the worst Barrel% (14.9%) in the game.
Is it sustainable? Well, McGreevy is a ground-ball pitcher by nature, even though he’s used the sinker less and seen more air contact. But for this week, he’s worth a grab. Tentatively, he’ll lineup to face the Mariners at home this upcoming weekend.
Moving on, Justin Wrobleski gets the Rockies on April 20. Wrobleski is a fascinating pitcher, one who mainly leans on his four-seamer/slider combo. He only has five strikeouts over 17 innings but he had the Mets’ number last week and proved to be hard to pick up.
Mitch Keller likely won’t go again until the weekend. However, he makes the list after a fantastic seven-inning shutout performance against the Rays. Keller now has a quality start in four of his first five outings this season.
Lastly, Caleb Thielbar picked up a win and a save over the weekend in Chicago. With Daniel Palencia on the IL, Thielbar appears to be the high-end reliever to own on the North Side.
Overview of Week 3
Finding consistent pitching this season has been a challenge. That couldn’t have been truer over the last week.
Javier Assad pitched great against the Mets on April 19, days after a disastrous outing against the Phillies. Joey Cantillo also played the Jeckyll & Hyde act on the 19th, as he had problems late in his start against the O’s, thanks to a Taylor Ward three-run shot.
But perhaps the biggest blow-up of the week came from Mike Burrows. Burrows gave up a ton of hard contact against the Mariners earlier this week, then rebounded to toss 4.2 spectacular innings against the Cardinals. Burrows didn’t allow a runner until Masyn Winn hit a ground-ball single — which turned into a four-run fifth and ultimately killed his line.
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