According to OptaSTATS, McLean is the only pitcher in MLB history to have a 2-0 record, sub-1.50 ERA, sub-.150 opponent batting average, 15 or more strikeouts, and fewer than five walks over his first two career appearances since 1913 — when ERA became official in both leagues.

McLean, 24, tossed 5.1 scoreless innings against the Seattle Mariners in his debut on Aug. 16, allowing two hits with eight strikeouts and four walks on 91 pitches. He then became the first Mets starter not named David Peterson to go at least six innings since early June, holding the Atlanta Braves to two runs on four hits with seven strikeouts over seven frames in his second outing.

The 6-foot-2 right-hander has averaged 3,295 RPMs on his curveball through two games — the highest average spin rate among all major league starters this season. His sweeper averages 2,965 RPMs, which ranks among the top three for that pitch. He rounds out his arsenal with a 96 mph fastball, 95 mph sinker, 91 mph cutter, and 86 mph changeup.

With that diverse mix of pitch shapes and speeds, McLean dominated both Double-A and Triple-A hitters before joining the Mets’ rotation. Between the two levels, he posted a 2.45 ERA, 1.13 WHIP, and 10.1 K/9 rate across 21 minor league appearances (18 starts) in 2025.

McLean currently ranks as the No. 3 overall prospect — and top pitcher — in the Mets’ farm system, according to MLB Pipeline. With Frankie Montas done for the season with a UCL injury, the door is open for other highly ranked Mets pitching prospects to get big league opportunities in long relief roles or as spot starters if the team expands to a six-man rotation.

After logging a 2.05 ERA over his last nine Triple-A starts, Mets No. 5 prospect Brandon Sproat pitched out of the bullpen for the first time this season Sunday, potentially foreshadowing New York’s plans. The right-hander allowed seven runs (five earned) on seven hits and two walks while striking out four over 3.2 innings behind opener Austin Warren, who gave up four runs in the first inning.

Another name to watch is No. 4 prospect Jonah Tong, who — according to Mike Puma of the New York Post — has put himself in the conversation for a call-up. The 22-year-old has fired 11.2 shutout innings with 17 strikeouts over his first two Triple-A starts and leads all minor leaguers in strikeouts (179) over 113.2 total innings this season.

Before either Sproat or Tong can make their next appearance, McLean will face his toughest test yet. He is scheduled to start Wednesday’s finale against the NL East-leading Philadelphia Phillies, who enter the three-game set with a seven-game lead over New York in the division standings.