Houston Astros pitcher Wandy Rodriguez gives a thumbs-up in the dugout moments after finding out that he had been traded to the Pittsburgh Pirates, during the fifth inning of a baseball game Tuesday, July 24, 2012, in Houston.

PITTSBURGH — The Pittsburgh Pirates had just lost consecutive home games for the first time in over two months.

Yet there was a sense of optimism in the Pirates’ clubhouse following a 5-1 loss to the Chicago Cubs on Tuesday night, even though they fell 2 1-2 games behind Cincinnati in the NL Central.

The Pirates were buoyed by the postgame announcement that they had acquired veteran left-hander Wandy Rodriguez from the Houston Astros in a trade for three minor leaguers.

It was the first time the Pirates had acquired a pitcher for a potential pennant push since trading with the Cubs for Danny Jackson in 1992. The Pirates won the NL East that season but haven’t been back to the postseason or even had a winning record since.

The Pirates will get up to $17.7 million in the deal to offset what could amount to over $30 million in salary for Rodriguez. They are sending Triple-A All-Star Rudy Owens and Colton Cain, both left-handers, and outfielder Robbie Grossman to Houston.

“We talked since Day One of the trading season about wanting to improve our club either via pitching or via hitting,” Pirates general manager Neal Huntington said. “The pitching market turned out to be more flexible than the hitting market and we decided this was the right move for us.”

The only player on the Astros roster remaining from their 2005 trip to the World Series, Rodriguez has been a steady presence on a rebuilding ballclub that has the worst record in the majors this year and lost 106 games last season.

Signed by the Astros in 1999, he is 80-84 with a 4.04 ERA in eight seasons. Rodriguez is 7-9 with a 3.79 ERA this year.

Pittsburgh manager Clint Hurdle believes Rodriguez will be helped by a change of scenery.

“I’m sure a change of clubhouses for him, a change of the dynamic of being in a situation (a pennant race) he hasn’t been in for three or four years should be helpful,” Hurdle said. “I’ve prepared for him for many years as a manager and as a coach. He has also been a tough pitcher to hit, a tough pitcher to beat. I’m very happy that we’re adding him to our rotation.”

James McDonald (10-4), who has been a mainstay of the Pirates’ rotation this season, had his career-best five-game winning streak snapped.

McDonald was touched for five runs and five hits in six innings while walking three and striking out six.

Starlin Castro and Alfonso Soriano both homered. David DeJesus hit a tiebreaking two-run double for Chicago, which had totaled just three runs in its previous four games.

DeJesus doubled to left in the fifth inning to put the Cubs ahead 3-1, the hit coming after Maholm drew a two-out walk to load the bases. Geovany Soto and Luis Valbuena, who had both also walked, scored on the double.

“I was actually pretty pleased with this outing,” McDonald said. “The ball came out of my hand really well. I felt like I had good command of my pitches, especially my curveball. They hit some good pitches and that’s going to happen sometimes.”