Hernandez, acquired in last year's trade for Gaby Sanchez, is on the 40-man roster but without any options left. He could either be traded or outrighted to Triple-A New Orleans.
Valaika, a non-roster invitee, won the utility infield spot over veteran Wilson Valdez, who will start the season in Triple-A. There are 30 players remaining in camp.
The 27-year-old Valaika, who last reached the Majors in 2011 with the Reds, played 33 games in two seasons with Cincinnati in 2010-11. During Grapefruit League action, Valaika is 12-for-50 (.240) with two homers and four RBIs.
"One thing [Marlins manager Mike Redmond] and I kind of talked about early on, he plays with a lot of energy and he's spunky and he's a grinder," Beinfest said of Valaika.
Valdez, 34, in Arizona most of the spring with the Giants, was released last Friday. He signed a Minor League contract with an invitation to Spring Training on Saturday.
In 36 spring at-bats, Valdez hit .174. He has played parts of seven seasons in the big leagues, including 2009-11 with the Mets and Phillies. He appeared in 77 games with the Reds last season.
Coghlan, the 2009 National League Rookie of the Year, is fully healthy after tearing the meniscus in his left knee while throwing a pie in a teammate's face following a walk-off victory.
The 27-year-old made last season's Opening Day roster before being sent down. He hit .140 with one home run and 10 RBIs in 93 at-bats.
With the most at-bats (61) in Grapefruit League action for the Marlins, Coghlan is hitting .311 with five doubles, one triple, one homer and seven RBIs in 19 games. He took advantage of time in center field while Justin Ruggiano nursed a lower back strain.
"He looked comfortable at the plate," Beinfest said. "I'm not sure we saw him comfortable or confident at the plate for a while. Really since he had the injury. … From Day 1 he's looked good. He really has. He came in swinging the bat and he hasn't stopped. I would say that's really one of the positives coming out of camp is the way he's played."
Hernandez hit .282 (11-for-39) with one double, eight RBIs and four stolen bases. The 25-year-old recorded the second-highest batting average (.367) in the Venezuelan winter league this past offseason.
"When we talk to these guys at this point in Spring Training it's all with the disclaimer that things can change," Beinfest said. "There are still a few days to go, but out of courtesy we're breaking camp today and let guys know where they're at."
With a 3 p.m. Sunday deadline to set the Opening Day roster, Beinfest said it would be finalized following Saturday afternoon's exhibition game against the Triple-A New Orleans Zephyrs.
Beinfest said non-roster invitee pitchers Kevin Slowey and John Maine remain in camp and are in contention to be on the club. A second catcher decision has not been made.
"When we leave New Orleans Saturday the club will be together and that stuff will be pretty clear," Beinfest said.