Syndergaard (2.60) finished third in the majors in ERA, followed by Bumgarner (2.74) at fourth.
"It's the big leagues. You're going to face great pitching in the postseason," Collins said. "I know they're in their clubhouse saying, 'Wow, we've got to face Syndergaard.' It should be a great game. ... They're a great team. They had a rough second half. Everybody knows that. But they're very talented. I know they're probably banged up a little bit like we are."
Syndergaard originally was slated to start Sunday's game against the Philadelphia Phillies if it turned out to be meaningful, but instead he threw a bullpen session at Citizens Bank Park and focused on preparing for Wednesday.
Syndergaard and Bumgarner squared off at Citi Field on May 1 in a 6-1 victory by the Giants. Syndergaard allowed four runs in 5⅔ innings and surrendered a two-run homer to Hunter Pence in that game, while Bumgarner tossed six scoreless innings.
Syndergaard rebounded to toss eight scoreless innings in a 2-0 win against the Giants on Aug. 21 at AT&T Park. Bumgarner allowed four runs -- all on a grand slam by the now-injured Justin Ruggiano -- in five innings in a no-decision earlier in that series. Bumgarner also homered against Jacob deGrom in that game.
"It's funky. [Bumgarner] is stepping at you and coming from behind you," Mets infielder Kelly Johnson said of the left-hander's delivery. "... The man can pitch. He's almost like a DH in the lineup, too. So we've got to worry about that. His track record speaks for itself.
"I don't think I have to sit here and talk about how good he is. It's going to be a tough game. It's going to be fun. I think being at Citi Field -- for us, winning the home field -- can't be stressed enough because that's a big swing in advantage for us, [and] not having to travel across the country, too."
Said Collins: "If you get balls to hit, you better hit them. Because if you let him get ahead of you, you're in trouble."
The Mets revived their season during that mid-August series at San Francisco.
After losing the opening two games at AT&T Park, the Mets had dropped to 60-62 and had fallen 5½ games behind the Cardinals for the second wild-card spot. However, Yoenis Cespedes and Asdrubal Cabrera returned from the disabled list during that series and the Mets took off, winning the final two games in San Francisco and ultimately going 27-13 to close the regular season.
Cespedes had three homers in the two games he played against the Giants in that series.
"We started to get our pieces back. There's no question," Collins said, reflecting on the series in San Francisco. "We knew we had to hold it together while they were out, and we did. We didn't win as many as we wanted, but we still competed. And when we started getting our pieces back, we knew we were going to be OK. Those young pitchers really helped us finish it off."
Cespedes' right quadriceps continues to nag him, although he minimized the injury Sunday.
"I think after I came back, the whole team collectively started to improve," Cespedes said through an interpreter. "And I think that's why we are where we're at now. I feel good. I think I'm ready physically and I'm ready mentally. That's the most important thing."