The career third baseman fielded only one ball, retrieving a double into the gap and getting the ball back to the infield in the Potomac Nationals' game against the Salem Red Sox.
Zimmerman has been on the 15-day disabled list since April 13, the day after he broke his right thumb diving into second base during a pickoff attempt.
The Nationals have several reasons to experiment with Zimmerman in left field. He was having throwing problems at third base before his latest injury, Anthony Rendon has played well filling in at third, and left fielder Bryce Harper is out until mid-July following thumb surgery.
Zimmerman went 1 for 3 at the plate.