PHILADELPHIA — Dave Roberts arrived at Citizens Bank Park just before 1 p.m. on Monday. He hoped to get a head start on a few things, namely the nearly 100 baseballs he needed to sign. It’s a time-consuming process, he explains, and it can be difficult, if not impossible, to find a time to do it without being interrupted.Sure enough, eight boxes of balls, stacked neatly on his desk, greet him as he walks into the manager’s office inside the home-side clubhouse.It’s a spacious and tidy setup, complete with two leather couches and a few extra chairs set up against a wall. But Roberts has no meetings on the docket, no last-minute things to address. Preparing to lead the National League in MLB’s annual All-Star Game is a song-and-dance he and his coaching staff are well-rehearsed in.As he prepares to manage his fourth All-Star Game, Roberts has agreed to let The Athletic shadow him and his coaches for the day. The entire Los Angeles Dodgers coaching staff, along with guest selections Don Mattingly of the Philadelphia Phillies and Oli Marmol of the St. Louis Cardinals, bustle through the clubhouse halls.Roberts plops into his chair and grabs a water, a Diet Dr. Pepper and a box of balls. Each player on the NL All-Star team will sign these balls, he explains, and MLB will auction off some of these mementos or use them for various charities. There’s also an autograph etiquette of sorts. The sweet spot is reserved for the manager’s signature. Players know to leave that space open if they sign before their skipper — or at least they should.But when Roberts grabs a ball out of the box, he sighs.“Come on, Yamamoto,” Roberts groans, spinning the ball to reveal his ace’s signature, scribbled dangerously close to Roberts’ designated space. “He should know better.”Roberts’ playful shot at Yoshinobu Yamamoto — one of six Los Angeles Dodgers to make the NL team — is timely. Because he started Saturday, Yamamoto won’t pitch in this year’s Midsummer Classic. In the room next door, pitching coach Mark Prior tries to pin down who will. Prior spent the last week communicating with pitching coaches around the league, analyzing workloads and availability and learning about any issues or concerns teams have about their star pitchers participating in this storied exhibition game.Prior walks into Roberts’ office with a detailed sheet showing all of the National League’s available pitchers. He’s just heard from the San Diego Padres and Washington Nationals with updates on Mason Miller and Foster Griffin, both of whom will be able to pitch, albeit with some limitations. But usage restrictions for starters on two other teams leave them with nine arms for nine innings, Prior says. Rarely does a pitcher in the All-Star Game record more than two innings, and Prior wants to ensure they don’t run out of arms.But before Prior and Roberts can finish the conversation, a member of the Dodgers’ public relations staff arrives to whisk the latter away to media duties. Roberts and John Schneider, the manager of the Toronto Blue Jays and the American League All-Stars, are due for a news conference with their selected starting pitchers. Prior retreats to the coaches room, where he and assistant pitching coach Connor McGuiness continue to map out the usage.The baseballs will have to wait.Dave Roberts was all smiles signing All-Star baseballs, at least until he saw that one of his pitchers took his sweet spot. (Katie Woo / The Athletic)It helps that Roberts has already made his most pressing pregame decisions. His starting lineup is set, with Philadelphia’s Cristopher Sanchez getting the nod as the starting pitcher.“I try to do it from the lens of: This is for the fans,” Roberts explained from his desk chair. “What allows for the fans to have the best experience? Their hometown guy starting the game is the way to do it.”He finalized his lineup with bench coach Danny Lehmann on the plane Sunday night. It’s helpful that the starting nine was decided by a fan vote weeks ago. But Roberts and Lehmann still had to decide on the batting order, something complicated by the seven left-handed hitters selected.