The Rockies optioned pitcher Steven Register to Triple-A Colorado Springs in a corresponding roster move. Register did not appear in any games since being recalled Tuesday.
Fuentes, who was available to pitch Friday in the first of three games against San Diego, has 26 saves this season and a 2.73 ERA with a 1-4 record.
Since July 3, Fuentes has converted 13 consecutive save opportunities while striking out 34 of the past 73 batters he's faced.
Reliever Jason Grilli recorded the only save in Fuentes' absence on Tuesday against the San Francisco Giants. Grilli became the fourth different Colorado pitcher to earn a save this season.
Corey Brock is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.