Houck (elbow) will make a fourth rehab appearance Saturday, and the Red Sox plan to evaluate him following the outing, Perla Paredes of MLB.com reports.
Houck was on the mound Tuesday for a third time during his rehab assignment. He struck out three while allowing one walk in a scoreless seventh inning for Triple-A Worcester. If all goes well Saturday, Houck could join Boston's bullpen for the final days of the regular season.