Reyes, the rookie right-hander and Cardinals top prospect, has pitched in just 21 big-league games during the past two seasons. None of them have carried the magnitude of an all-important Game 4.
Still, the right-hander is trying to stay on an even keel.
"I just have to look at it as it just another ballgame," Reyes said after the Cardinals' 5-0 victory Saturday night. "I just have to go out there and stick to my gameplan and let my stuff take over, and hopefully I can keep the ball down and come away with a win."
Reyes, who was not even on the roster for the Division Series against the Padres, received the Game 4 nod over inconsistent right-hander Jason Marquis, who is not active for the best-of-seven series.
"I'm excited," Reyes said. "Growing up, I dreamed of playing in the playoffs and World Series, and to get my opportunity, I'm excited."
This will be the Reyes' first work since the last game of the regular season. He allowed four earned runs in two-thirds of an inning against the Brewers, but the appearance was under very unusual circumstances.
The Cardinals needed either a win or a Houston loss to clinch a playoff spot, and had Chris Carpenter as the scheduled starter. Cardinals manager Tony La Russa, though, held back the ace for the playoffs and told Reyes he would start the morning of the contest. Reyes, throwing on three days' rest for the first time in his career, was ineffective.
Since then, Reyes has thrown several bullpen sessions, played catch and watched a lot of baseball games.
"It's been tough," Reyes said of the layoff. "They just said, 'Stay prepared, stay ready because you never know what will happen.' I just kept doing my routine and came out, and they told me that I would be pitching in this series, so I was very excited."
Rest, though, has helped Reyes tremendously this year. In early September, Reyes -- finishing the first full season of his professional career without injury -- allowed seven runs in 2 1/3 innings against the Diamondbacks.
Afterward, Reyes said he was pitching with a sore arm. He was skipped the next time through the rotation and pitched brilliantly his next two outings, striking out 15 hitters and permitting just three runs in 11 1/3 innings.
Those two starts were indicative of Reyes' potential -- potential that made him the top prospect in the Cardinals' system entering the season.
Because of an injury to Mark Mulder and disappointing starting pitching, the right-hander -- on course for a full season in Triple-A and a spot in the 2007 starting rotation -- found himself as one of the Redbirds' five best starters in late June.
In one of the first starts of his career, Reyes dazzled the White Sox, tossing a one-hitter. He didn't work that far into a game the rest of the campaign, but was usually solid for five or six innings. Still, he had trouble being aggressive and often threw 90 to 95 pitches in his starts.
From June 27-Aug. 16, the right-hander made nine appearances and worked fewer than six innings in eight, but allowed three runs or fewer in five of the outings. His confidence a little deteriorated, he was sent down to Triple-A Memphis when Mulder returned to the rotation in mid-August.
The decision was an outstanding move -- Reyes pitched two shutouts in the Minors, reclaiming his pitches and confidence.
"Those past two games were probably the best I have thrown since I got here," Reyes said when he returned to the Majors after Mulder suffered a season-ending injury. "I was using the fastball like I used to. I was throwing the fastball and working it off all of my other pitches, as opposed to throwing more offspeed pitches."
His confidence restored, Reyes tossed six innings of shutout ball in his first start back, displaying a revamped pitching philosophy. Instead of trying to pick at corners, the rookie went right at hitters, using his four-seam fastball early in counts, setting up a fine breaking ball and an above-average changeup.
The philosophy yielded much better command and location. During his last five starts this year, he enjoyed a 4-to-1 strikeout-to-walk ratio and punched out 28 hitters in 20 2/3 innings.
"I always have my gameplan set at nine innings," Reyes said. "I just go for as long as I can, and when they decide to take me out, then they can take me out."
Reyes will need to have full command against an explosive Mets' lineup that includes MVP candidates Jose Reyes, David Wright and Carlos Beltran.
"Location would probably be the biggest thing," Reyes said. "I'm going into this thing just thinking it's a regular baseball game, not trying to think about anything else and just going out there and making my pitches."
Conor Nicholl is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.