Irving, who attended Game 1 and sat on the bench during the first half, was not spotted inside TD Garden for Game 2, but his teammates said his words of encouragement helped them before Tuesday's 120-106 triumph.

"[Irving] sent us a message before the game today, just telling us what to expect," said Shane Larkin, one of Boston's ball handlers thrust into a larger role due to Irving's season-ending knee surgery.

"We have a lot of guys in here that have never seen a playoff game," Larkin said. "So he really gave some words of advice today and we all read it, made some comments back, and he just had an open conversation with us and he's definitely helping off the court now that he can't be out there with us fighting.

"He's definitely still locked in with us every single game."

It's notable that Celtics players have gone out of their way to praise Irving's leadership, particularly when juxtaposed to a situation like San Antonio and the lingering uncertainty surrounding Kawhi Leonard.

The Celtics have won their first two games of the playoffs in large part because of the contributions of players such as Terry Rozier, who hasn't committed a turnover in 78 minutes of floor time since elevating to a starting role in place of Irving.

For 21-year-old Jaylen Brown and 20-year-old Jayson Tatum, Irving's leadership and playoff experience is even more valuable.

"Kyrie talked to us before the game, just kind of let us know what to expect, a lot of things to expect, and for us to stay locked in, and not worry about if we hit some adversity or whatever, just play through it," said Celtics All-Star big man Al Horford. "And I thought our guys just did that. [The Bucks] made a run and we stayed poised and moved on to the next thing."

The Celtics are navigating the early stages of the playoffs with only 11 healthy bodies. Irving, Gordon Hayward, Marcus Smart and Daniel Theis are all out for Boston. Smart is hoping he can return from thumb surgery by a potential Game 7 of a first-round series.

For the younger players forced into elevated roles, Irving is a steadying voice.

"[Kyrie's message] means a lot," said Horford. "Part of the reason we're in this position -- and it's obviously tough for us not to have him -- but he's still trying to find a way to contribute. Nice to have him there."

The Celtics sent rehabbing Hayward to work with a running mechanics specialist in Indianapolis as the next step in his recovery from a fractured ankle suffered on opening night. Celtics coach Brad Stevens joked before Tuesday's game that Boston was "trying to get [Hayward] ready for Friday's [Game 3]," eliciting laughter from reporters before stressing again that Hayward is not anywhere near a return to basketball activities.

"He's not going to join us in Milwaukee if that answers your question. He's still a long, long, long, long way away," said Stevens, who has been inundated with questions about a possible Hayward return throughout the season.