By CBSBoston.com Staff

BOSTON (CBS) — Robert Williams had himself one heck of a game Sunday night, but the Celtics big man didn’t think much of his 22 minutes against the Pacers. For Williams, his solid night was ruined by one play.

Following Boston’s 108-107 loss in Indiana, Williams wasn’t focused on the 12 points that he scored in the contest. He wasn’t focused on getting some crunch-time minutes, a sure sign that he’s earned some of Brad Stevens’ trust.

He was instead focused on one slip-up that he believes cost his team the game.

After the loss, Boston forward Jayson Tatum shouldered the blame for missing a game-winning three at the buzzer. But Williams wanted his share of the blame pie as well, pointing out that if it wasn’t for his defensive mix-up one play earlier, the Celtics may not have needed that last-second shot by Tatum.

“I feel like I’m definitely coming along, making progress. But like I said, I’m not coming along fast enough slipping up like this,” he said after the loss.

Williams is talking about Indiana’s final play of the game, when trailing by one, center Domantas Sabonis had the ball at the top of the key. The Pacers big man faked a handoff, which Williams fell for. That misjudgment left Williams scrambling and gave Sabonis a clear path to the hoop. Williams couldn’t recover in time and was late to Sabonis, whom he fouled as the Indy center put in a layup.

Sabonis hit one of his two free throws, with Williams corralling the miss for his fourth rebound of the night. After head coach Brad Stevens called a timeout, a visibly upset Williams slammed the ball to the court.

Following the loss, Jaylen Brown said the entire Boston defense failed on the Sabonis layup due to their lack of communication. Still, Williams feels like that one play sullied the rest of his evening.

“I feel like at the end of the day we didn’t stop them when we were supposed to. We messed up the defensive coverage, so really, all the other stuff goes out the window,” he said.

It’s too bad Williams feels that way, since he had a strong performance against the Pacers. In addition to his 12 points off 6-for-7 shooting, he pulled down four rebounds and had four steals. He also came up with a big defensive play down the stretch when he stripped T.J. Warren with 15 seconds, leading to a go-ahead layup from Marcus Smart with 11.8 seconds left.

Three seconds later, Sabonis’ driving layup rendered that previous play somewhat meaningless to Williams and the Celtics.

While Williams was his own biggest critic on Sunday, Stevens was very pleased with the energy that Williams displayed on the court. It had the C’s head coach turning to Williams in crunch time over seasoned bigs Tristan Thompson and Daniel Theis.

“Played hard. He played really hard,” Stevens said of Williams. “Obviously, we were very low energy in the third quarter and that cost us the game. Any time you give up 40 in a third quarter on the road to a good team, you’re probably going to lose. To our guys’ credit, they hung in there and got back in the game. But Rob was one of the reasons why, because he brought a good deal of energy to the table.”

But it didn’t matter how much praise he received from his head coach or his teammates. Williams was more caught up on what he didn’t do on the floor.

“I was brought in the game to bring the energy, so that’s what I was trying to do. But like I said, we messed up the coverage. Me personally, I messed up the coverage,” he echoed.

Williams and the Celtics will look to make all the right plays when they play the Pacers again on Tuesday night.

CBSBoston.com Staff