The Astros have designated first baseman Carlos Pena and shortstop Ronny Cedeno for assignment, reports Brian McTaggart. Shortstop prospect Jonathan Villar is being promoted from Triple-A Oklahoma City to take Cedeno’s spot on the roster. CSN Houston reports that Villar will be the team’s starting shortstop tomorrow.

Villar was acquired along with Anthony Gose and J.A. Happ from the Phillies on July 29, 2010 in the Roy Oswalt trade. In 385 trips to the plate at Triple-A, Villar posted a .786 OPS, including a marked increase in power in what has been the best season of his professional career.