For roughly two months after the all-star break this summer, Carlos Beltran didn’t look like himself at the plate. The world-class slugger went from dominating pitchers and being discussed as an MVP candidate to suddenly losing his rhythm in the batters’ box.

His batting average in July and August shrunk to .206, and despite the widespread knowledge that he was playing with lingering knee and hand problems, Beltran insisted he would find a way out of the slump. And as the seasons started to turn, so did Beltran.

“He started to get hot at the end of the season and you could tell, we just needed to get him to the playoffs,” Cardinals starting pitcher Adam Wainwright said. “He has such a great history in the playoffs, that really is his time. . . . He’s a proven playoff commodity.”

Despite the fact that this October marks only his third postseason appearance in his 15-year career and his first since 2006, Beltran is well established as one of the top playoff performers of his era thanks to a bat that can’t be quieted in the fall.

In just 25 postseason games, Beltran has scored 34 runs, 13 of them on homers, 22 RBI and the best slugging percentage (.819) in postseason history. For all of Beltran’s stunning individual statistics, though, he has yet to appear in the World Series.

The pursuit of a championship was why the Puerto Rico native decided to sign a two-year deal with the Cardinals last December. Back in the playoffs for the first time since he lost in the 2006 National League Championship Series to St. Louis as a member of the New York Mets, Beltran is glad to have another chance to reach his elusive goal.

“Who doesn’t love to play in these types of games, where you are fighting to win a championship?” Beltran said after he belted a pair of home runs in the Cardinals’ 12-4 win over the Nationals on Monday. “For me, I’m going to enjoy it because you never know when you are going to get another chance to be in this situation.”

For the Cardinals, who lost Albert Pujols to free agency over the winter, Beltran’s addition has been a good fit. He helped replace some of the offense that departed with Pujols and for the first time, St. Louis wouldn’t be on the receiving end of Beltran’s postseason exploits.

Both of his previous appearances — in 2004 with the Houston Astros and in 2006 with the Mets — ended with NLCS losses to the Cardinals, but not until after Beltran racked up 20 runs, seven homers and nine RBI in those two series combined.

In 2006, it was Wainwright who struck out Beltran on a curveball for the series-winning out that eliminated the Mets. Wainwright is happy they’re on the same team this time around.

“I was fortunate enough to get that out but [former Cardinals manager] Tony LaRussa was probably about ready to have my hide for walking to load the bases and face Carlos Beltran,” Wainwright said. “When he’s on your team it’s always nice to see him at the plate during the playoffs. But being on the opposite side of that matchup for a few years, that’s a bat you really don’t want to face.”

The Nationals shouldn’t need a reminder of that, given that in seven regular season games against them this year he recorded seven RBI, three runs, two homers and six hits. But Beltran’s pair of homers in Game 2 of this National League Division Series gave them one anyway. It was a not-so-friendly hint that leaving a pitch in the middle of the plate is essentially gift-wrapping it for Beltran.

At 35, there’s no telling how many more opportunities Beltran will have. Which is why he’s determined to do everything he can to help St. Louis advance this time.

“In my case, I’m just trying to go out there and help the team any way I can,” Beltran said. “I would love to have that opportunity but at the same time I understand it’s hard to win a championship.”

Many members of the Cardinals clubhouse already have a World Series victory on their resumes. While there’s no questioning their drive to become the first team to repeat as champions since the Yankees did so in 1999 and 2000, players such as Beltran who haven’t won it all add a different element to the team’s overall motivation.

“It is always good to have that veteran presence that has not quite won the ring yet,” Manager Mike Matheny said. “You saw last year the Cardinals really rally around Rafael Furcal, who had been in the postseason so many times. The guys just . . . it means a lot to them, there’s no question. It’s also nice to see Carlos Beltran start to really get locked in like he was [Monday].”