When Will A.J. Puk., Luis Arraez, George Kirby Return? Fantasy Baseball Injury Update

When will Puk, Arraez, Kirby return and play? Will Puk, Arraez and Kirby be back again this season? Read the latest fantasy baseball injury updates and return date for Week 4 of the 2025 MLB season.

Even though we are just four weeks into the MLB season, injuries have begun to pile up. Fantasy managers have seen high-end players hit the injured list and, as a result, have needed to look to the waiver wire for replacements.

In this piece, we will analyze the latest injury update for Arizona Diamondbacks relief pitcher A.J. Puk (elbow), San Diego Padres infielder Luis Arraez (concussion), and Seattle Mariners starting pitcher George Kirby (shoulder).

Should fantasy managers expect these players back in their lineups soon? Let's dive in!

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A.J. Puk Injury Update For Fantasy Baseball

A.J. Puk was enjoying a solid start to the young season as he logged eight innings to the tune of a 3.38 ERA with a 1.25 WHIP. He tallied four saves and two holds, operating as the top high-leverage option in the Arizona bullpen.

However, after his appearance on April 17 when he picked his fourth save of the season, the Diamondbacks announced they placed the 29-year-old on the 15-day injured list due to left elbow inflammation.

We have made the following roster moves: pic.twitter.com/VCg2FygnmL

— Arizona Diamondbacks (@Dbacks) April 19, 2025

On Monday, Jody Jackson of the team reported that the southpaw was set to undergo an MRI on Monday to determine the extent of the injury.

A.J. Puk felt soreness in his left elbow after his last outing in Miami. He is going on the 10 day IL and will be evaluated including an MRI back in Arizona Monday.

— Jody Jackson (@Jody_Jackson) April 19, 2025

Fantasy managers should pay close attention to any updates regarding Puk, as a further setback could significantly delay his recovery window. While Puk is sidelined, fantasy managers should expect young right-hander Justin Martinez to operate as the clear ninth-inning option in the desert.

Through the early part of the season, it appeared Puk was the "1A" of the closer committee in Arizona. However, with Puk on the injured list, Martinez should be the clear front-runner for save opportunities.

However, Martinez was unable to pitch over the weekend due to "fatigue" issues, which could eventually open the door for Shelby Miller or Drey Jameson to see a handful of save situations.

Before his injury, Puk generated impressive metrics that make him worth holding in standard category leagues. The left-hander generated a 2.86 xERA with a .211 xBA, which were both well above the average marks. Puk also generated an elite 34.3 percent strikeout rate with a 25.0 percent hard-hit rate.

When he does return, he should be in line to see the majority of save opportunities on a competing Diamondbacks team.

Luis Arraez Injury Update For Fantasy Baseball

Luis Arraez was removed from Sunday's contest after a collision at first base. He had to exit the game on a stretcher and was sent to a hospital for further evaluation.

Fortunately, Arraez was able to avoid a significant injury and was placed on the 7-day injured list with a concussion. Arraez will have to miss at least the next seven games until his concussion symptoms pass.

Luis Arraez will be placed on the 7-day IL.
He is in the concussion protocol.

— Kevin Acee (@sdutKevinAcee) April 21, 2025

Fantasy managers should continue to monitor his status, but if the 28-year-old continues to progress, he could return to action as early as next week. Before his injury, the first baseman was starting to find his swing, as he posted a strong .338/.380/.500 slash line with three doubles and three home runs over his last 18 contests.

He began the season going 0-for-13 with just one walk over his first four contests.

Arraez has won a batting title in each of the previous three seasons. During this impressive stretch, Arraez has posted an overall .328/.371/.426 slash line with a stellar 5.6 percent strikeout rate.

While Arraez remains sidelined, fantasy managers should expect Gavin Sheets and Yuli Gurriel to share time at first base.

Fantasy managers in both category and points leagues should continue to stash Arraez in all formats as he will provide a significant boost to your team's batting average while carrying one of the best strikeout rates in the sport.

George Kirby Injury Update For Fantasy Baseball

The final player we will check in on is George Kirby of the Seattle Mariners. Kirby has been sidelined since the first week of March due to right shoulder inflammation. Later in the month, the team reported that Kirby received an injection and was eventually able to begin playing catch towards the end of the month.

George Kirby had 20 throws from 60 feet. He will bump up to 75 feet tomorrow. The Mariners have it mapped out with some days off from throwing scheduled. He said the biologics shot in the shoulder definitely helped the process.

— Ryan Divish (@RyanDivish) March 21, 2025

However, as expected, at the start of the season, the Mariners placed the 27-year-old on the 15-day injured list.

On April 7, Daniel Kramer of MLB.com reported that Kirby had "felt great" while throwing a bullpen session and was slated to progress to the next step. Kramer also noted that a return in May was "possible."

George Kirby “felt great” when throwing a bullpen this weekend, per Justin Hollander. He'll throw two more ‘pens this week and then begin more of a traditional game progression.

No official timeline yet, but sounds like May is more likely at this point.

— Daniel Kramer (@DKramer_) April 7, 2025

Earlier this week, Kirby received very positive news as he was cleared to face live hitters for the first time since suffering the injury. According to Kramer, Kirby is expected to face hitters at T-Mobile Park.

Sources: George Kirby is expected to throw a live batting practice this week at T-Mobile Park, which would mark the first time that he's faced hitters since his early-March shutdown with right shoulder inflammation.https://t.co/163AcDi56c

— Daniel Kramer (@DKramer_) April 21, 2025

Fantasy managers should keep a close eye on his status throughout the week, as he could be nearing a rehab assignment if he does face any setbacks following the throwing session.

After a modest MLB debut in 2022 when he posted a 3.39 ERA with a 1.21 WHIP across 130 innings, Kirby has been one of the most effective WHIP boosters in the major leagues. Over the past two seasons (2023 and 2024), Kirby has logged a cumulative 381 2/3 innings, to the tune of a strong 3.44 ERA and a stellar 1.05 WHIP.

During these two years, Kirby has tallied 351 punchouts with just 42 walks.

While he does not carry high strikeout upside, he will provide a significant boost to your team's WHIP ratio. As a result, fantasy managers should continue to stash Kirby on their injured reserve in all formats.

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