BOSTON — The sweat was still pouring off Robert Williams’ head as he greeted a reporter after Celtics’ summer league practice on Tuesday. The team’s media relations staff had plucked Williams out of the weight room for a quick chat and it was obvious he had been working up a big sweat on what was supposedly a light day for the summer team.

A day earlier, Williams had told reporters about how coach Brad Stevens had given him some inspirational words that essentially screamed: Hey, look at our frontcourt depth chart right now, there’s an opportunity here for anyone who wants it.

But we wanted to know more about what exactly Stevens had stressed to Williams and what he was doing with the message.

"Hard work and effort, obviously,” said Williams, dabbing at the sweat on his face with his practice jersey. “Just recognizing that I’m not looked at as a 21-year-old. It’s about picking stuff up, learning how to play with guys, learning how to be comfortable, more than anything. And putting in the work.”

While Williams talked, the Celtics were putting the finishing touches on a slew of signings to fill up a previously barren frontcourt. It started with getting veteran Enes Kanter to agree to a two-year, $10 million pact Monday utilizing the midlevel exception. Daniel Theis, a restricted free agent, agreed to a deal with virtually the same terms. Boston also imported French 7-footer Daniel Poirier on a minimum salary deal, adding to a diverse-yet-largely-unseasoned collection of bigs.

Kanter, Williams, Theis, and Poirier will compete for frontcourt minutes with Guerschon Yabusele, Semi Ojeleye, and rookie Grant Williams. (And before you scream: What about Tacko Fall?! Let’s wait until after summer league to project whether he can make an NBA roster, though the 7-foot-6 big man is undeniably fascinating to watch).

Kanter, with eight years experience and coming off a solid postseason showing in Portland, would seemingly project as the team’s starting center. Still, the Celtics are going to give Williams every opportunity to wrestle away minutes. Kanter is hired help as the team tries to plug holes and remaining competitive after the departures of Al Horford, Aron Baynes, and Marcus Morris. But Boston’s most ideal path forward is finding a young impactful big who can develop alongside Jayson Tatum and Jaylen Brown.

Enter Timelord, whose initial NBA aloofness endeared him to Celtics fans but who is acutely aware of the opportunity now within in his grasp, should he be willing to fight for it.

“Definitely, I feel like I [have an opportunity to earn minutes],” said Williams. "Obviously, that’s what we’re here grinding for. The opportunity that Coach keeps saying is in front of me. So you gotta put in the work.”

Williams, the 27th pick in the 2018 draft, landed in headlines last year after oversleeping his post-draft conference call then missing a flight for the team’s first summer league practice. When he did get in games, he tantalized fans with his athleticism, throwing down alley-oop lobs and swatting shots six rows deep in the crowd.

Williams logged only 283 total minutes in 32 appearances. He got a spot start in Charlotte late in the season — not his finest night — and played sparingly down the stretch (though, in his other start in the regular-season finale, he put up two points, 11 rebounds, three blocks in 29 minutes while helping Boston rally for a win in Washington).

What did Williams learn last season? That it’s a long year. That opportunities are going to arise. He seems to acknowledge now that he wasn’t always ready for them. He might be now and he’s trying to prove it to the coaching staff. Williams wants to show he’s ready to be on the court for long stretches.

“You want to improve on everything but I’ve been working on my conditioning, every day,” said Williams. "I feel like that’s a big factor for me. A lot of my moves are explosive, defensively and offensively. I feel like I have to get the conditioning part under me.”

Asked Monday how hungry he was to prove himself at summer league, Williams answered, “Starving.” Now he has to prove it. Some health woes limited him to only two minutes of court time at summer league this year. This year's trip to Vegas is the perfect opportunity for Williams to show that he deserves time.

The summer coaching staff has reminded him that he’s a “veteran” on this group, one of only two Celtics players (Yabusele the other) returning for summer action. And early signs have been encouraging.

"I’ve been real happy with [Williams],” said assistant coach Scott Morrison. "He’s showed some toughness, showed some leadership, being one of only the only two returning Celtics players that we have on the roster here. Hopefully, he hangs in there and can really show well for himself in Vegas.”

Stevens is going to have all sorts of options in the frontcourt this season. Who plays might ultimately hinge on who shows they want it more and who best impacts winning.

Williams has all the talent to earn big minutes. But he’s gotta put in the work. He certainly seems willing. As soon as the brief interview ended, before the sweat on his brow had even dried, he jogged across the gymnasium and right back into the weight room to complete his workout.

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