Nunez has blown two saves in his last two outings -- Saturday night vs. St. Louis and on Thursday against Philadelphia -- and he also allowed three hits and a run in a non-save situation on Wednesday against the Phillies.
"We're trying to get him to use his fastball more," Rodriguez said. "We've been using the bullpen way too much, and that may be the reason he doesn't want to go with the fastball. For now, he's our closer, but if he doesn't make an adjustment, we may have to explore other options -- maybe do a closer by committee."
Despite this week's rough outings, Nunez has still had a strong season, with a 2.91 ERA, 49 strikeouts and 12 walks over 46 1/3 innings. After giving up 13 homers in 2009, he has given up just one this year.