3) 2008 Johan Santana
The Mets acquired former two-time Cy Young winner Johan Santana in a blockbuster deal during the 2007-2008 offseason. His first season in New York was one of the best of his career, as he set a career-best in ERA at 2.53, pitched a career-high 234.1 innings, and his 166 ERA+ ranking was the second-best he ever had in a single season.
However, despite a dominant year, Santana didn’t make the All-Star game. It’s not like he didn’t have the numbers to earn a roster spot. Santana entered the All-Star break with a 2.84 ERA, 3.65 FIP, and 1.19 WHIP across 126.2 innings pitched. He struck out 21.7% of opponents with a 6.7% walk rate. His +2.5 fWAR was one of the highest marks in baseball.
Santana was in the top ten of multiple stats heading into the break. His ERA was the fourth-lowest among all NL-qualified pitchers. The lefty ranked 8th in FIP. Santana’s K:BB ratio was the 7th highest. He also came in with the 9th-lowest WHIP. He was tied with Carlos Zambrano in fWAR, where Zambrano made the All-Star game. The only rate stats Santana wasn’t top ten in was his walk rate, which ranked 18th in, and HR/9 (0.99), clocking in at 27th.
Brewers’ Ben Sheets ended up getting the nod for the All-Star game for the National League team, and while he was having a strong season, he had very similar numbers to Santana. Sheets owned a 2.85 ERA, 3.43 FIP, with a 21.7% K%, 5.6% BB%, and 0.95 HR/9 ratio in 123 innings. If those sorts of numbers earned Sheets the opportunity to take the mound to open the 2008 All-Star game, then Santana’s should have been good enough to at least make the mid-summer classic in the first place.