The Philadelphia Phillies avoided offseason heartbreak by inking Aaron Nola to a seven-year, $172 million contract. Now, the focus shifts to Zack Wheeler’s future. The Phils’ top ace is due $23.5 million in 2024 before hitting free agency. While there’s a chance Wheeler and Philadelphia agree to terms on an extension, there’s an even greater chance that Wheeler tests his value on the open market.

If it gets to that point, the Phillies run the risk of losing their best pitcher. Wheeler finished sixth in NL Cy Young voting last season, posting a 13-6 record in 32 starts. He managed a 3.61 ERA and 1.076 WHIP, punching out 212 batters in 192.0 innings pitched. At 33 years old, Wheeler’s fastball can still push the high 90s, with extension in the MLB’s 97th percentile, per Baseball Savant.

He’s a tough at-bat for even the league’s most disciplined and dynamic hitters. Wheeler also carries his share of postseason experience at this point. The Phillies don’t want to lose him, and as evidenced by the Nola contract, the Phillies are comfortable with long-term guarantees. Philadelphia also offered the most money of any team to free agent Yoshinobu Yamamoto. There are a couple ways to read that. On one hand, it’s further evidence of the front office’s aggression. On the other, it’s fair to wonder if Philadelphia would offer that much to Yamamoto if there is confidence in Wheeler’s longevity with the franchise.

Either way, the Phillies need to get a head start on scouting potential replacements. The 2025 free agent class has no shortage of quality arms, and trades are always on the table. Here is who Philadelphia should monitor.

Roki Sasaki currently plays for the Chiba Lotte Marines of the Nippon Professional Baseball League in Japan. At 22 years old, he is too young to be signed as anything more than an amateur prospect in the MLB. That means he will suffer the financial restrictions inherent to amateur prospects unless he waits until 2026.

Whether he puts it off that long or not, Sasaki is coming down the pipeline — fast. He requested to be posted in December but will stick it out in Japan for at least one more season. He is more of a long-shot, long-term replacement for the Phillies to monitor, but Sasaki merits attention all the same. The talented righty caught scouts’ attention with a 19-strikeout perfect game in 2022.

The Phillies are known to be angling for a more expansive presence in the Asian market. Despite never meeting with Yamamoto in person, the Phils offered him more money than even the Dodgers. One has to believe that once Sasaki is available to MLB bidders, Philadelphia will be in the mix.

In theory, it’s the perfect approach for the Phillies front office. Sasaki is talented enough to contribute out of the gate, but he would also (presumably) join Philadelphia with a long window of team control. Rather than replacing Wheeler with another vet on the decline, the Phillies could replace him with an up-and-coming star with the potential to produce at a high level for the next decade-plus.