Predicting when Padres prospect Miguel Mendez will make his MLB debut in 2026

Michael King's return to the San Diego Padres was obviously a sigh-of-relief moment, as the team desperately needed a co-ace to pair with Nick Pivetta after losing Dylan Cease (free agency) and Yu Darvish (injury) over the past few months.

King's presence gives Craig Stammen far more flexibility in the rotation, and there's now a path for the Friars — led by Pivetta, King, and Joe Musgrove — to field an above-average starting pitching group in 2026.

However, things are still largely uncertain after that trio, with Randy Vásquez and JP Sears the current favorites to win the final two jobs in the rotation. Talented though they may be, that's not a world-beating quintet.

Thus, there's clearly room for a breakout pitcher to take a spot and run with it next season. And if any of Padres' prospects are going to do that, it'll be Miguel Mendez.

Miguel Mendez's MLB debut may be decided by necessity, not readiness

Mendez, 23, was protected from the Rule 5 Draft back in November, meaning he's already on the 40-man roster. That'll ease any logistical tensions in getting him up to the big leagues, but it's important to remember that he's only thrown 22 1/3 innings above High-A.

Yes, he's incredibly talented. The Padres' No. 2 overall prospect according to FanGraphs, Mendez paired a 3.22 ERA and 3.86 FIP with a 29.4% strikeout rate and .208 batting average allowed in 95 innings last year across three levels.

However, he struggled in Double-A to conclude his season. His 8.06 ERA and 5.91 FIP were the results of an inflated walk rate (15.9%), which points to the rawness of his arm. He's still relatively early on in his development, even if he can expect a quick promotion to Triple-A thanks to his roster status.

In terms of pure readiness, Mendez probably wouldn't make his MLB debut until late 2026 (when rosters expand in September) or early 2027. But the Padres' lack of quality starting pitching depth could force him into a prominent role far more quickly.

As one of nine teams to exceed the luxury tax threshold in 2025 — and facing the prospect of a franchise sale some time in the next 12 months — the Padres' resources may already be spent. Mendez may not start the season in San Diego, but a hot start to the campaign could make him the next man up on the depth chart.

If everything breaks the Padres' way in 2026, expect to see the talented righty some time after the trade deadline. If not... well, he can get some on-the-job training in San Diego.