Reyes, who has three hits in his last 20 at-bats, was not in the starting lineup for Friday's game against the D-backs.
"I think Jose needs more of a break mentally than physically," Marlins manager Ozzie Guillen said.
The shortstop has hit just .205 with a .263 on-base percentage and .329 slugging percentage through 18 games this year. Friday marked the first time he did not start as a Marlin.
"I think if you see his at-bats -- I don't want to say just in New York, but on the road trip -- he was rushing at the plate," Guillen said. "He was trying to do too much, and I think that's the reason he's struggling. But it's not just Jose. There are a lot of guys on our club that are struggling right now. We're trying to come out of it the quickest we can. We're working on it."
Donnie Murphy filled in for Reyes at shortstop and batted second, while speedy center fielder Emilio Bonifacio took over leadoff duties for Reyes, moving up from his usual second slot in the lineup. Bonifacio has been one of the better hitters this season for the Marlins, batting .261 while posting a .354 on-base percentage.
"I'm proud of Boni," Guillen said. "Boni has come a long way. Boni played in every league in baseball to get where he is right now. He went through everything and now he is a big league player playing very well. He's very mature. He has a lot of confidence in himself. I tip my hat to him, because I know this kid went through [a lot] to make it to the big leagues and now he's an everyday big league player."
A lifetime .291 hitter, Reyes is off to his worst start since becoming an everyday player in the big leagues. But he is working hard to get back on track. The 28-year-old put in extra work with Marlins hitting coach Eduardo Perez prior to the team's usual batting practice on Friday.
"People have to realize you cannot get five hits in one at-bat," Guillen said. "You cannot hit a three-run home run with only one guy on base. Don't let the game play you. Just try to relax and do what you're supposed to do. Everybody here has a job. Don't try to do somebody else's job. That's the way you have to approach it at the plate."