Andres Blanco, who was activated on Friday from the 15-day disabled list with a fractured left index finger, took Franco's place at third base. Blanco was originally placed on the DL on July 25 and hadn't played since.
It marked Blanco's 29th start this season, and 10th at third base. He started 13 games at second base, five at shortstop and one at first base.
"I'm just going to back off, just to let this settle down on his hand and to give him a blow, because he's obviously pressing, getting a little frustrated," Mackanin said of Franco's day off.
Franco is 0-for-8 over the first two games of the road trip in Miami, and has gone hitless in five of his last eight games. Struggling during the recent stretch, Franco is hitting just .182 in his last 33 at-bats.
He's still the power hitter the Phils are looking for at the hot corner. Franco leads the team with 22 homers, 73 RBIs, 44 extra-base hits and 212 total bases. He's the first Phillies third baseman to hit 20 homers in one season since Scott Rolen (25) in 2001.
However, things have not been going well lately. Franco hasn't hit a home run since Aug. 18, and he has just one RBI in his last 14 games, with an extra-base hit in just one of those games.
The Eastern League named Reading outfielder Dylan Cozens, the Phillies' No. 7 prospect according to MLBPipeline.com, as the league MVP on Wednesday. The 22-year-old Cozens hit .276 with 40 homers and 125 RBIs. He also scored 106 runs and had a .591 slugging percentage.
Cozens led all Minor League players in homers and RBIs this season, and is just the second Phillies Minor League player since 1963 to reach 40-plus home runs. Ryan Howard accomplished the feat with 46 homers in 2004.
In addition, first baseman Rhys Hoskins was named the Eastern League Rookie of the Year, while Dusty Wathan earned Manager of the Year honors. Hoskins hit .281 with 38 homers and 116 RBIs.
Glenn Sattell is a contributor to MLB.com and covered the Phillies on Wednesday. This story was not subject to the approval of Major League Baseball or its clubs.