The Marlins optioned the first baseman to Triple-A New Orleans on May 20. By league rule, barring replacing someone who was placed on the disabled list, any player optioned must stay at least 10 days in the Minor Leagues before being brought back up.
"Needless to say, we're keeping our eye on him," Marlins president of baseball operations Larry Beinfest said. "We're tracking him every day and talking to our people. We want him to be confident and comfortable."
An All-Star in 2011, Sanchez has struggled at the big league level, batting .197 with one home run and 11 RBIs in 36 games.
Since being optioned, he's played in nine games with the Zephyrs, batting .300 (9-for-30) with a home run and four RBIs. Sanchez had an eight-game hitting streak going before he went 0-for-4 on Monday.
"Gaby has always hit," Beinfest said. "He hit pretty much immediately when he came to the Major Leagues. For him not to hit is a little bit off the tracks, and it's not something we anticipated. Let's get him really feeling good about himself and comfortable."
Logan Morrison has been playing first base since Sanchez was sent down.
"Logan is doing a fine job at first, and his bat looks like it's waking up a little bit," Beinfest said. "We'll just take it as a positive and do what we've got to do."