"This is the best I've seen him," Manuel said Tuesday. "He was good at the end of last year, but not as dominant as he's been this season."
Santana was the NL Pitcher of the Month last September, when he went 4-0 with a 1.83 ERA. He was 3-1 this April, but his 1.10 ERA was the best for a Mets pitcher in his first five starts in 20 years.
"Real impressive, real impressive," Manuel said of Santana's work. "To have a loss with the stuff he's had is indicative of how our offense has been, not anything he did."
Santana was originally scheduled to start Tuesday night against Atlanta, but Sunday's rainout in Philadelphia pushed him back. He wasn't with the team when his April award was announced Tuesday, having been given the perk of flying back to New York early to get a night's sleep in his own bed before facing the Phillies.
Philadelphia obviously would have liked to miss him during the two-game series in New York, just like the Phillies did last weekend at home. Santana is 2-0 with a 2.85 ERA in six career games against the Phils.
Few teams have fared well against the native of Venezuela. This was the eighth time Santana has been the Pitcher of the Month. He won the honor six times in the American League with Minnesota.
Santana, 30, won the AL Cy Young Award twice while with the Twins in 2004 and '06. His career record in 112-52.
In his first season with the Mets last year, Santana went 16-7 with a Major League-best 2.53 ERA. He led the NL with 234 1/3 innings pitched and was second with 206 strikeouts.
Even by Santana's standards, his early work this year has been eye-popping. He has 44 strikeouts in 32 2/3 innings, allowing just 22 hits and nine walks.
Hall of Fame pitcher Don Sutton, now an Atlanta broadcaster, puts Santana high on his list of favorite pitchers.
"As his resume gets a little longer, he could rank up there with some of the best," said Sutton, a 324-game winner. "He has a mind presence and a grasp of pitching that I sit and watch and admire.
"He seems to have an innate sense of what to throw and when to throw it that doesn't just come from a scouting report. He has a little voice inside him. The good pitchers have that sixth sense. He's as polished as anybody pitching today."