Jason Castro was having a good day during a strong start to a season that could soon be deemed All-Star worthy.

Then Jose Altuve stamped Castro with true All-Star approval.

While the third-year Astros catcher was soaking up the personal reward that came with his 10th home run of the year during his team’s 5-4 victory over the Chicago White Sox at Minute Maid Park before an announced crowd of 25,829 on Sunday, the fun-natured Astros second baseman looked over at rookie center fielder Brandon Barnes and made a confession.

“You’re not my favorite guy anymore,” Altuve said jokingly. “Now, it’s Jason.”

Castro soon learned the face of the rebuilding Astros had elevated him to the peak of his personal most-popular list.

For a 25-year-old who spent the last two seasons struggling with major injuries and watching the shine of being the No. 10 overall pick in the 2008 MLB draft start to dull, hearing about Altuve’s in-game honor was another reason to take pride in his 2013 resurgence and the spirit of a young team that continues to play better than almost anyone expected.

“We’ve got a great group of guys, and you can see that looseness kind of coming back,” said Castro, who’s hitting .270 with 23 RBIs, leads the club in slugging percentage (.476) and doubles (18) and ranks second in hits (60). “When you have that fun atmosphere to baseball in the clubhouse, that’s when you can really put together your best baseball.”

The Astros are 16-14 in their last 30 games, have won four consecutive contests and are on the verge of sweeping a four-game series from the light-hitting White Sox (28-38).

The surge provoked Astros (26-44) owner Jim Crane postgame Sunday to reach out and shake first-year manager Bo Porter’s hand, then say, “Congratulations. Good work.”

That left Porter praising a star-less team for its will and determination.

“I give these guys credit, I give the staff credit, I give this entire organization (credit),” Porter said. “Everybody stayed positive and comes to the park each and every day ready to fight the next day and put out maximum effort.”

Castro has played a critical part in the resilience. The former Stanford standout was one of the Astros’ premier players during spring training and showed signs of being on the verge of a breakout.

He started the regular season slowly, though, hitting just .207 with a .548 on-base plus slugging percentage through April 19 and was stuck at a .237 batting average May 17.