HOUSTON -- As Yordan Alvarez shattered multiple rookie and team records during the regular season, it was often easy to forget that the Cuban slugger is just 22 years old. But postseason struggles have shown that even Alvarez isn’t immune to the rookie learning curve.

After a dominant rookie season, it’s almost a given that Alvarez will win the American League Rookie of the Year Award next month. Despite not making his debut until June 9, the 22-year-old hit 27 home runs and broke numerous records along the way. His seven home runs in his first 12 games marked an Astros record, the 16 RBIs in those 12 games marked a Major League record and the 72 RBIs in his first 71 games tied Ted Williams (1939) and Rudy York (1937) for second-most in MLB history. Only Walt Dropo (80 in 1949-50) had more runs batted in through his first 71 games.

Alvarez’s rise turned an already feared Astros lineup into a juggernaut. His left-handed bat was inserted into the middle of the order, giving more balance to Houston's righty-heavy lineup. Alvarez’s addition helped the Astros finish third in the Majors with 5.7 runs scored per game.

But the postseason has painted a different picture for Alvarez. Through 11 postseason games, he is slashing .171/.227/.244, including a 1-for-22 performance in the ALCS against the Yankees, and he has yet to hit a home run in 44 plate appearances. In the regular season, Alvarez’s longest homerless drought was only 32 at-bats, from June 25-July 12.

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So what exactly has been different for Alvarez?

To start, he’s facing better pitching, which is to be expected in the postseason. He’s also facing more left-handed pitching as teams have game planned against him. Tampa Bay, for example, carried four left-handers in the bullpen, just to ensure that Alvarez would face a southpaw in every key situation. The Yankees had Aroldis Chapman and Zack Britton at their disposal.

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During the regular season, Alvarez faced a left-handed pitcher in 35.5 percent of his plate appearances. In the postseason, that number has increased to 45.5 percent of the time. Not only is Alvarez facing more southpaws in October, but he’s struggling to produce against them. Alvarez finished the regular season with a 1.038 OPS against lefties, but that number is down to .308 in the postseason. The Nationals will have Patrick Corbin and Sean Doolittle available to face Alvarez.

“I believe in Yordan,” said Astros manager AJ Hinch. “We get to wipe the slate clean. He gets to start all over again in the World Series, and he’s going to be facing some elite pitching.”

Aside from facing more left-handed pitching, Alvarez has also had mixed results against breaking pitches during the postseason. The designated hitter went 5-for-10 on breaking balls against the Rays in the ALDS, but he went 0-for-10 with nine strikeouts vs. offspeed against the Yankees in the ALCS.

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“I think one of my issues was that I was a little anxious,” Alvarez said. “But that anxiousness came from not finishing the regular season strongly. Then I dragged those struggles at the end of the season into the postseason. But I think those struggles are behind me and I’m just trying to do the best I can from this point forward.”

During the playoffs, Alvarez is still getting opportunities to hit a fastball, but he has struggled to capitalize. Opposing pitchers have thrown Alvarez a fastball 63 percent of the time during the postseason, which is up from a 59 percent clip during the regular season. Alvarez finished with 13 home runs and a .652 slugging percentage against heaters in the regular season, but he is just 2-for-21 on four seamers in the first two playoff series.

A fastball up in the zone and a breaking ball in the dirt have been the game plan against Alvarez during the postseason. Alvarez, however, isn’t overly concerned and believes he can turn it around during the World Series.

“I think you can notice my struggles more because we’re in the postseason,” Alvarez said. “There were times in the regular season that I struggled. Not exactly like this, but similarly. I was able to get out of that, and I think I’ll be able to get out of these bad moments now.”

Hinch said the plan in the World Series is for Alvarez to hit seventh and DH during the first two games, but his role is unclear once the series shifts to Washington and the designated hitter is no longer in play.

The Astros have plenty of weapons in the starting rotation and the lineup, but Alvarez seems like the wild card in this series. Houston is averaging just 3.7 runs per game during the postseason, but if Alvarez can provide some of his regular season production, the Astros could win their second World Series in the last three seasons.

“We need him to be good, to be at our best,” Hinch said. “And I look forward to him DH’ing both Game 1 and 2. We’ll see what happens when we get to Washington.”