Lidge, 31, went to the DL March 24 to continue recovering from right knee surgery performed Feb. 25.
The move was retroactive to March 21, but it was decided that Lidge was not ready to return at that time.
"Physically, I feel fine," he told The Philadelphia Inquirer. "I think facing some major-league hitters will bump up my velocity a little bit more to where I'd like to be."
This week, Lidge threw his fastball more the 90 miles an hour during a session in Clearwater, Fla.
In six season with the Astros, he compiled 123 saves and a 3.30 ERA.
In 2004, he joined Eric Gagne to become the only relievers with three straight 100-strikeout seasons.