Will Warren can recite the mistakes. He remembers — and has pored over the video of — that 3-2, middle-of-the-plate fastball to the Angels’ Zach Neto back on Aug. 7.

“He taught me a lesson. I’ll never make that mistake again,” Warren said this week. “After the game, Gerrit [Cole] was like, ‘Let’s throw your best pitch here because at the end of the day, if you walk him, you walk one run in. A fastball down the middle, you let four runs in.’”

In his second ever major league start, the promising prospect allowed eight runs, half of those on the Neto grand slam, in 4 ⅓ innings in which he struggled and learned. It was one lesson of many during a rough first taste of major league life for Warren, who is spending his offseason — and already spent his postseason — studying his missteps.

The Yankees will need the right-hander to take in that knowledge, adjust and improve because he might be their first option when the first inevitable rotation injury strikes.