Sanabia appeared in five Grapefruit League games, and he made two starts, the most recent on Saturday against the Nationals in Viera. He had a 5.14 ERA in seven innings.
"Sanabia did a nice job," manager Mike Redmond said. "He just needs to go down there and prove that he can stay healthy and take the ball every five days. That's most important for him."
Hand made two relief Grapefruit League outings, giving up four runs in three innings with five walks and two strikeouts.
The main candidates for the fifth-starter spot are Wade LeBlanc, Kevin Slowey, Tom Koehler and John Maine.
Sanabia and Hand were among nine players the Marlins sent to the Minors on Monday.
The team also optioned right-hander Evan Reed and outfielder Kyle Jensen to New Orleans.
Right-hander Sam Dyson, lefty Edgar Olmos and outfielder Marcell Ozuna, who is ranked the organization's No. 7 prospect by MLB.com, were optioned to Double-A Jacksonville.
Right-hander Jordan Smith and catcher Wilfredo Gimenez were re-assigned to Minor League camp.
Ozuna, a power-hitting right fielder, is projected to be in the outfield with Christian Yelich and Jake Marisnick at Jacksonville. Ozuna, Yelich and Marisnick are ranked the club's Nos. 7, 2 and 3 prospects, respectively, by MLB.com
Ozuna was impressive, batting .364 (4-for-11) with one home run and four RBIs in seven Grapefruit League games.
"This has been good," Ozuna said of being in big league camp. "I learned how it is to be here."
Redmond was impressed with the power of Ozuna and Jensen.
"We got them some at-bats in big league camp, and they did a great job," Redmond said. "I think the great thing for me is, obviously, we talk about the big number, 74 guys [in camp]. But, what's good for me is, I got to see a number of these guys play -- alot of these guys that the organization considers some of our best players.
"It's good for me to see these guys and what they can do, and what they need to continue to work on."