Rosario said the condition is related to sweating more in warmer weather, and doctors told him it would clear up if he doesn't wear long sleeves beneath his uniform top. That isn't a problem in the recent 90-plus degree temperatures.
"You can see, there's nothing," Rosario said, showing clear skin. "I'm clear. I don't have anything. This is a false alarm."
Rosario also thanked fans for their concern. The issue was revealed Thursday.
The Rockies did not comment on the condition, citing privacy restrictions.
Rosario, who had been playing with the biopsy site on the inside of his right elbow taped and bandaged, can now attack his hitting slump with a relieved spirit. Rosario was batting .239 with 10 home runs and 32 RBIs entering Friday's game, but hit just .133 with one homer and five RBIs over his past 17 games.
Thomas Harding is a reporter for MLB.com. Read his blog, Hardball in the Rockies, and follow him on Twitter @harding_at_mlb. This story was not subject to the approval of Major League Baseball or its clubs.