Montanez played with the Orioles earlier this season, but he was placed on the 60-day DL after tearing a ligament in his right thumb.
"I was actually coming out of salsa lessons," Montanez said. "They were ringing my phone like crazy and I was in a salsa lesson working my hips. And when I got in my car, I saw the messages."
MacPhail already had turned to Montanez's agent, who was in Greece.
"It was like a mission all over the world just to get in contact with me," Montanez said. "It was like, 'Where is Carmen San Diego?'"
Montanez, who batted .204 in 18 games with the Orioles earlier this season before being placed on the DL May 26, was activated off the DL on Saturday.
He was in Miami after a brief stint with Double-A Bowie, where he went 3-for-8 with two RBIs.
Montanez was shifting his thinking toward winter baseball.
"I was laying back, watching college football, not doing much," Montanez admitted before Saturday's game with the Red Sox. "I was a little bit surprised, because I thought everybody was healthy and they were going to finish out the season. I didn't expect to be up here, but you've got to make the best of it. I haven't really been swinging in like two weeks."
Montanez was not in the starting lineup Saturday, but he was happy to return to the Orioles' clubhouse. Teammates hugged Montanez and shook his hand as he hurried to get to his locker.
"I think what he needs to do is play catch, run around, take some fly balls and get ready," said manager Dave Trembley. "I can't tell you when he's going to play, if he's going to play, how much he's going to play. I have to take a look at it and see where he's at."
Matt Palmer is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.