The Dodgers have been short-handed in the bullpen since Nicasio left Wednesday night's game with the injury, which he said originally surfaced during his two-inning start at Coors Field June 2.
Nicasio threw 16 fastballs in Sunday's game, even though manager Don Mattingly said Nicasio reported he could throw sliders.
The fingernail injury cropped up just when he had emerged as a candidate to set up for closer Kenley Jansen, a role that has been in flux with injuries to Pedro Baez, Joel Peralta, Brandon League and Paco Rodriguez, along with the inconsistency of Chris Hatcher, Yimi Garcia and J.P. Howell.
With so many relievers on the disabled list, and Nicasio's injury expected to heal in days, the club kept him active since Wednesday while Mattingly managed with a limited bullpen.
Mattingly said Peralta (pinched neck nerve) came out of his second rehab appearance for Class A Advanced Rancho Cucamonga on Saturday night well, while showing improved velocity, and he might throw back-to-back there Monday and Tuesday.
Rodriguez (elbow spur) will join Peralta there Monday to begin a rehab assignment, while Baez (strained pectoral muscle) will meet the club next week in Los Angeles, after throwing bullpen sessions in Arizona, and is getting close to a rehab stint. League still needs several more rehab appearances, after being sidelined for nearly four months.
Outfielder Scott Van Slyke (strained back muscle), 1-for-4 as designated hitter for Rancho Cucamonga on Saturday night, will play the outfield there Sunday and first base on Monday before it's decided when he will return from the disabled list.
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.