With Saturday's release of Russell Branyan, the team's three-man rotation at first base has cleared up, giving the 28-year-old Miranda his first look at consistent playing time.
"It feels better to get more of a chance to play now," Miranda said.
In 75 at-bats this season, Miranda is hitting .253, with two home runs and six RBI. Xavier Nady will back him up.
"It's difficult sometimes to play one game and then sit two games," he said. "It's difficult to get in a rhythm."
D-backs manager Kirk Gibson said that the team looked at both the present and future when reaching its decision to release Branyan.
"Ultimately, we thought we were going to watch [Juan] play and let him get more reps," he said. "He's never really had an opportunity in the big leagues to play much."
Miranda was signed by the Yankees as an amateur free agent in 2006, before being traded to the D-backs last offseason. He has 158 Major League at-bats over four years.
He recorded a career-high three hits in Thursday night's win over the Braves.
"I think it's good to get an opportunity to get into the game every day," he said.