4 Pittsburgh Pirates Rule 5 prospects who have made the case for a 40-man roster spot

Every season is a chance for prospects who are going to be Rule 5 eligible to make a case for a 40-man roster spot. The Pittsburgh Pirates have plenty of notable names in their minor league system, and they will have to make a choice at the end of the season that could determine a few test case's organizational fates. They should have enough 40-man roster spots to protect some important minor leaguers, but some notable ones will likely end up getting exposed to the draft either way.

If they protect anyone, these four should be the first ones they consider.

4 Rule 5 eligible prospects the Pirates should protect

Antwone Kelly

Antwone Kelly entered the year as an unheralded name in the Pirates' system. He was signed out of Aruba during the 2020-2021 offseason and excelled throughout short-season levels of the minor leagues, but he didn't perform well in 2024 at Bradenton, his first big test as a pro pitcher. Since that line in the sand, Kelly has quickly put his struggles behind him with an outstanding 2025 season thus far.

The 21-year-old started the year at Greensboro, where he tallied 59.1 IP and put up a 3.03 ERA, 2.81 FIP, and 0.98 WHIP. Kelly saw his walk rate drop from 11.3% in 2024 to 7.4% at Greensboro, while his strikeout percentage rose from 21.7% to 30.4%. Kelly also put up a 0.61 HR/9 ratio. That led to a call to Double-A Altoona, where his numbers have been solid.

He has 43.1 IP at Double-A, putting up a 2.70 ERA, 3.02 FIP, and 1.04 WHIP. His K% has fallen to a still respectable 24.4% rate, and he continues to post an 8.1% walk rate that helps the bottom line. The long ball continues to be a non-issue for Kelly, with a 0.49 HR/9 ratio. While the league Altoona is in is very pitcher-friendly this year, with a league-average OPS of just .681, keep in mind that Kelly is doing all of this while being the second youngest pitcher across all of Double-A with at least 40 IP.

Baseball America currently has Kelly as the Pirates' 12th-best prospect. His fastball has seen an uptick in velocity and can hit triple-digits. He also flashes an above-average slider and an improving changeup. It's hard to imagine Kelly getting completely glossed over when it comes to making 40-man roster decisions this offseason, given that high-upside potential relievers are the easiest type of player for a thieving organization to stash. Kelly has done everything he can to avoid the Rule 5 Draft and get a chance with Pittsburgh. 

Wilber Dotel

Wilber Dotel is another right-handed pitching prospect who had some unimpressive numbers in 2024. He struggled at Greensboro, but has made some significant improvements to his overall game in 2025. That has resulted in a promising season that will likely end with him landing on the Pirates' 40-man roster.

Dotel's 4.41 ERA at Altoona doesn't tell the entire story. He is striking out about a quarter of opponents with a 24.9% strikeout rate, and cut his walk rate down from 11.6% to 7.3%. Home runs have also become far less of an issue this season. His HR/9 at Greensboro was 1.78, but has fallen to 1.06 as he's leveled up. Despite a mediocre ERA, he has a 3.83 FIP and 3.53 xFIP that indicate positive performance could be around the corner. Other teams see that, too. 

Another thing that makes Dotel look better than his ERA is the quality of his stuff. He sits in the mid-to-upper-90s and can hit triple-digits. He saw a step forward in fastball velocity in 2024, and that has carried over into 2025. His other offerings give him great velocity separation. Dotel's two-seamer sits closer to the lower 90s, and his slider and changeup sit around the upper 80s. 

Like Kelly, it's hard to imagine Dotel not getting a 40-man roster spot. A pitcher who can hit 100 MPH and doesn't allow many walks as a starter would get instantly picked up in the Rule 5 draft.Both have made some real strides in terms of prospect rankings. Dotel is only 22 and at Double-A, but there's no reason for the Pirates not to protect him from the draft. 

Esmerlyn Valdez

The Pirates don't have much hitting in the farm system, but Esmerlyn Valdez could be a future answer at first base or a corner outfield position. After a promising 2024 season, Valdez was promoted to Greensboro to open the year, and hit .303/.385/.592 with a .447 wOBA and 175 wRC+ over his first 314 plate appearances. He hit 20 home runs, and cut his K% down significantly from 30.4% in 2024 to just 24.5% with the Grasshoppers. 

After a scorching hot start, the Pirates gave Valdez the opportunity to play at Double-A Altoona at the beginning of July. His first 121 plate appearances have had their ups and downs. July was a rough month for Valdez, as he turned in a .621 OPS, .292 wOBA, and 83 wRC+. He struck out 17 times with no home runs through his first 60 plate appearances. The month of August has been much kinder to Valdez, as he is putting up a .760 OPS, .351 wOBA, and 122 wRC+ in 57 plate appearances after shaking off a potentially serious injury. He still has 15 Ks in that span, but has gone yard twice. He has also drawn nine walks to go along with his power. 

Valdez is also still young, as he is just 21 years old. He is the 21st youngest player across all of Double-A with at least 120 plate appearances. He definitely has the sort of powerful upside the Pirates need. Both MLB Pipeline and Baseball America project his power to be a 60-grade. Valdez has an arm that could play in the outfield, but his lack of range will likely limit him to first base long term.

First base prospects don't usually get picked up in the Rule 5 draft. Only three first base prospects have been selected in the Major League portion of the draft since 2015, given that whoever stashes them must keep them on the active roster all year or lose them once again. Advanced bats typically don't get left in limbo. Valdez's ability to play an outfield corner spot, as well as his powerful upside (even with some risk attached to his hit tool), would make him a prospect a team may be willing to take a chance on as a project if he hits the open market.

Brandan Bidois

Brandan Bidois is an unranked prospect in the Pirates' farm system. The Pirates signed the right-hander out of Australia during the 2018-2019 offseason. Bidois got off to the best start of his career in 2025, pitching to an outstanding 0.86 ERA, 2.72 FIP, and 1.14 WHIP over his first 21 innings of the year. He struck out over 30% of opponents (with a 31% K rate) and allowed no home runs. Limiting walks has always been an issue for Bidois, and this stretch was no different. His 14.9% walk rate was not good, but it was the only blemish on his report card at Greensboro.

This outstanding start earned him a call to Altoona, where he has only gotten better. Bidois has tossed 25 more frames, working to a 1.08 ERA, 2.13 FIP, and 0.72 WHIP. He has kept up an outstanding 28% strikeout percentage, but more impressively has significantly cut down on walks issued, with just an 8.6% BB% at the higher level. Bidois has yet to allow a home run and has improved his ground ball rate from 26.1% at Greensboro to 46.4% at Altoona.

Bidois is a relief prospect through and through. He hasn't started a game since 2021, and his stuff works best out of the bullpen. His four-seam fastball sits mid-90s and can hit 99. Bidois takes off a lot of velocity on his curveball, coming in around the mid-70s, and can hit 3,000 RPM with the pitch. His third pitch is a cutter/slider-type offering. 

There are still some red flags about Bidois. His command isn't excellent, even with improving control, and his .189 batting average on balls in play likely isn't sustainable. The Pirates have found success with many relievers over the last few years. Bidois could definitely add to that list next year. It seems unlikely the Pirates would leave Bidois off the 40-man roster, especially given there is a decent chance another team would pick him up in the Rule 5 draft.