The Pirates are focusing their quest for pitching help on left-hander Wandy Rodriguez of the Astros, MLB.com has learned.

There is no confirmation from either side of a tentative deal having been struck, but the sides are close enough to an agreement that the Bucs have for the time being pulled the plug on other prospective deals involving a left-hander.

Rodriguez may already have begun the process of undergoing the pre-requisite physical before the deal becomes official, although no announcement is expected Tuesday night.

The Cubs’ Paul Maholm, the recent member of the Pirates’ rotation, and Minnesota’s Francisco Liriano had been other southpaws of interest.

Pittsburgh GM Neal Huntington first inquired on Rodriguez during the offseason, when the Astros made it known he was available. Rodriguez was one of several veteran starters under consideration until the Bucs decided to sign Erik Bedard.

Rodriguez, 33, is 7-9 in 21 starts for the Astros, with a fine ERA of 3.79. He tendered a quality start Monday night against the NL Central leading Reds, holding them to three runs in six innings.

The native of the Dominican Republic has a career record of 80-84 and is in the middle of a three-year contract. He is earning $ 10 million this season and is due to earn $13 million in 2013. There also is an option for 2014 at $13 million, with a $2.5 million buyout.