Dietrich, competing for a roster spot, expects to wear the protective face guard for about 10 days. He's only using it in the field, not when he is batting.
"I'll wear it the next 10 days or so, and then I should be good to go without it," the left-handed hitter said.
Dietrich is expected to return to Grapefruit League action Tuesday against the Cardinals.
If Rafael Furcal (left hamstring) opens the season on the disabled list, Dietrich is a candidate to fill in.
Joe Frisaro is a reporter for MLB.com. He writes a blog, called The Fish Pond. Follow him on Twitter