"It's one of the big reasons why I decided to put my daughter on it -- it's just another way to stay active and be creative with it. I don't like to just post pictures of rackets, so if I meet someone cool, or go to an interesting place..."
Micaela, too, is getting to see the world. And she's being primed for a life in tennis -- already boasting a racket deal "after a long 16 months of negotiations" according to a post on her Twitter page in June.
"I played tennis my whole life so I would love for her to play tennis, because for me it was amazing," says mom Michelle, a lawyer who played the sport at college.
"I developed mentally, I think I benefited from it growing up, all my friends played tennis -- the culture is something I want her to experience as well. But ultimately it's up to her."
Micaela may still be getting to grips with her nascent tennis swing, but she's already a dab hand with technology -- though more often than not it ends up in her mouth.
"She's a genius with the iPhone, she loves it. She's got the swiping down," says Mike, as he retrieves his mobile from the baby before it receives a terminal dribbling .
"We love having her on the road. That's the only way Bob would do it. He wants to see her develop and grow up, and we've seen her first steps, we see her roll over for the first time. And I'm a good babysitter -- I ask for $100 and I'll do it."
Life on the tour can be a grind, but having a baby on board can alleviate some of the stress.
"She doesn't care if we win or lose, so it keeps things in perspective," says Bob.
"We lost a tough one in Monte Carlo and had seven match points. We wouldn't usually talk for a few days, but she comes running at us, gives us a hug and laughing, she doesn't care."
Micaela may soon have company on the circuit -- Michelle is pregnant again. And the brothers have no intention of quitting yet.
"We're still having fun, we're eager, we still have some goals left," says Mike.
Bob: "We're perfectionists, I still don't think we're playing our best tennis. There's stuff we can improve and you want to get to that level before you shut it down."