Reliever Henry Rodriguez will begin a minor league rehab tonight in Class AA Harrisburg by throwing two innings. Rodriguez, the flamethrower right-hander the Nationals received from the A’s in return for Josh Willingham, began the season on the 15-day disabled list after neck spasms threw his delivery off kilter.

At most, Rodriguez can spend 30 days on his rehab assignment. The Nationals have no set timetable and they will evaluate Rodriguez after tonight’s performance. They seem willing to let him spend plenty of time righting his delivery in the minors, in part because they would have to take a reliever off their roster (and, if they want to recall any reliever to the majors, Collin Balester would potentially take priority).

“When you bring somebody on, that means somebody’s got to go,” Manager Jim Riggleman said. “So you’ve got to be real careful about when we make that decision. I’m not anticipating too quickly. I don’t think it’ll take him long physically. I think it’s going to come down to if he’s having success.”

The Nationals have two other rehabbing pitchers making progress. Minor-league reliever Rafael Martin, the 26-year-old the Nationals signed out of the Mexican League last spring, stayed in Florida in order to regain comfort with his delivery following a longer offseason than he is accustomed to because of his unique background. General Manager Mike Rizzo expects him to join a minor league team – either Harrisburg or Class AAA Syracuse, most likely – within a week.

Chien-Ming Wang, meanwhile, is “continuing his progression,” Rizzo said. (Stop us if you’ve heard that one before.) Wang will likely throw a minor league game in Nationals extended spring training within a week or so, Rizzo said.