The first baseman, who is the team leader in average, home runs and RBI, is making good progress and is close to returning.
"Townsend is hitting extra batting practice, taking ground balls and running the bases," Keys manager Orlando Gomez said following Friday's game.
Gomez added that he hopes Townsend can return to the team by Monday or Tuesday at the latest.
Mummey is slowly progressing along and Gomez feels he is a little ways away from returning to the lineup and in center field.
"We are expecting Mummey to be at least another week maybe two at the latest." Gomez said.
Both players have missed the past 12 games and were injured on May 8 against the Potomac Nationals. The team is 4-8 in their absences.