PHOENIX -- Zack Wheeler was 32 years old when he threw the first postseason pitch of his life. At an age when some of his contemporaries had already retired, Wheeler -- a onetime top prospect who for years battled injuries, then the resulting perception that he was something less than an ace -- opened a new chapter of his career.

“There was definitely curiosity,” Wheeler said of his initial playoff experience last year. “I mean, you know what type of stuff you have, and I’ve had good seasons before last year, so you want to carry it into the playoffs. But everybody’s game steps up a little bit also.”

Just not like this. This is abnormal. Few have accomplished what Wheeler has in a growing sample of postseason work.

In holding the D-backs to just one run over seven innings in the Phillies' 6-1 win in Game 5 of the National League Championship Series on Saturday night at Chase Field, Wheeler further cemented what is becoming a bona fide legacy: He is, without question, one of the finest postseason pitchers of his generation.

“He’s an all-time competitor,” teammate Kyle Schwarber said.

The numbers back that up. With seven more innings, one run, eight strikeouts and a walk on his ledger, Wheeler improved his career postseason ERA to 2.48 over 10 starts. Consider also:

• Wheeler’s 0.73 WHIP is the lowest by a pitcher in any 10-start span in postseason history, as well as the lowest by anyone with more than 50 innings pitched.

• He’s one of only five pitchers to strike out at least 34 batters while walking two or fewer over a four-game postseason stretch, joining Cliff Lee, Stephen Strasburg and Josh Beckett.

• The only starters in playoff history with at least 60 innings, an ERA below 2.50, a sub-1.00 WHIP and at least one strikeout per inning are Wheeler and Hall of Famer Bob Gibson.

“It’s cool. It’s special. I take pride in it,” Wheeler said. “There’s been a lot of great pitchers that pitched in the postseason. A bunch of them probably have more innings and body of work than I do, but I try to do the best I can with what I have.”

Although Wheeler ran into small pockets of trouble in Game 5, including a runners-on-the-corners, one-out jam in the first, he recorded key strikeouts at the most opportune times -- of Christian Walker that inning, and of Pavin Smith when another runner reached third base with one out in the sixth. Teammate Bryce Harper referred to it as Wheeler’s “slow heartbeat” -- a trait that, whether literal or not, has allowed Wheeler to thrive in the most significant games.

“There were some key at-bats and some key moments where, if we slugged, it’s a totally different outcome,” D-backs manager Torey Lovullo said. “But he made pitches and kept us in check.”

Asked about his ability to throw with such crispness and consistency, Wheeler points to the Tommy John surgery he underwent in 2015 -- one that robbed him of that entire season, including what would have been his first career playoff run with the Mets.

Recovering from surgery, Wheeler said, “I had a lot of time to tinker and fool with stuff,” including an arm path adjustment designed to protect his right elbow. Wheeler bounced ideas off then-teammate Jacob deGrom, himself a veteran of Tommy John surgery. Wheeler also studied other top pitchers around the league.

Then, he became one of them, both in terms of durability and effectiveness. During this age in which teams are asking increasingly less of their starting pitchers, Wheeler has shouldered a burden well above the norm. No one else has lasted into the seventh inning at least three times this postseason. A day after the Phillies used six pitchers in a crushing Game 4 loss to the D-backs, Wheeler completed seven innings on just 99 pitches (69 strikes). It was the exact sort of length the Phils needed to have a chance at attacking Game 6 on Monday at something close to full strength.

“I know the bullpen was taxed a little bit, so I needed to go deep,” Wheeler said. “And, obviously, I wanted that to be quality innings.”

If Philadelphia can qualify for the World Series, Wheeler will be lined up for Game 1 on Friday night. If an NLCS Game 7 becomes necessary on Tuesday night, it’s not outlandish to think he could even appear for an inning in that one. The Phillies have come to rely on Wheeler as much as anyone.

They all know it. Following Game 5, Harper approached Wheeler to tell him he’s “one of the best pitchers I’ve ever played with.”

“I’ve played with a lot of good ones, and he’s easily top three,” Harper said later, relaying the conversation. “It’s so much fun to watch. I love playing behind him, and it’s incredible. He’s legit.”