"Dobbs, I need to get him some at-bats," manager Ozzie Guillen said. "I can't leave a guy on the bench for a couple of weeks and expect him to get a hit. That's why we did it."
Dobbs is the Marlins' primary left-handed pinch-hit option. He started in place of Gaby Sanchez, who is 1-for-11.
"Gaby, I think is a little anxious," Guillen said. "From my perspective, he's a little anxious, trying to do too much. He tries to put a lot of pressure on himself."
Guillen made it clear that Sanchez was sitting on Sunday only to give Dobbs some action.
"He's not playing because I need to get Dobbs to get some at-bats," the manager said. "[Sanchez] needs to relax a little bit and stay with his program. This ballclub is about 25 guys, it's not about one.
"We need 25 to contribute. Nobody on this ballclub is that good to carry the ballclub. One day, one guy. One day, another guy."
The Marlins will be playing back-to-back afternoon games, with a 1:05 p.m. ET start at Philadelphia on Monday.
Left fielder Logan Morrison is expected to get the day off then. Morrison had surgery on his right knee in early December, and he is getting periodic off-days.
"Everybody on this ballclub can contribute," Guillen said. "We don't have to wait for Hanley [Ramirez] to get hot, or [Emilio] Bonifacio to steal four bases. Everybody here has a chance to contribute every day. That's what we want."