WASHINGTON — Isaiah Thomas feels as though he was shut down by the Washington Wizards and the referees in Game 4.

Thomas said after the Boston Celtics’ 121-102 loss Sunday that the officiating needs to change as the second-round series continues after the Wizards played him hard in holding him to two points after the first 15 minutes.

“They were very physical. The refs were allowing them to hold and grab and do all those things,” Thomas said. “It’s got to be called differently. … I can’t be allowed to be held and grabbed every pin-down, every screen and I don’t even shoot one free throw. I play the same way each and every night. That has to change.”

Thomas acknowledged that the Wizards’ 26-0 third-quarter run was the reason for the result, not the officiating. But with the series returning to Boston for Game 5 on Wednesday, he began to lobby for more calls after not going to the free-throw line once.

The 5-foot-9 All-Star guard had 53 points in the Celtics’ Game 2 overtime victory and was bottled up with 13 and 19 in Washington. He started Game 4 shooting 5 for 5 from 3-point territory with 17 points and was held to two more on 1-of-7 shooting the rest of the way.

“They obviously were locked into him the whole game, but obviously more so after the barrage of 3s,” Celtics Coach Brad Stevens said, crediting the Wizards for switching and sticking on Thomas off pick-and-rolls. “They were really up into him.”

Being physical was the plan with Thomas, Wizards guard Bradley Beal said. Coach Scott Brooks complimented his big men for keeping their hands up to avoid fouling Thomas, but Beal was more than willing to make contact when necessary.

“Our goal is just take him out of the game and just continue to be physical with him,” Beal said. “He runs around the floor all day, I’ve been chasing him all first half. I just wanted to come in and just be physical with him.”

Containing Thomas is no easy task. Games 3 and 4 marked the first time in his NBA career that he fell short of 20 points back to back. When he had five quick 3s Sunday, it looked like another opportunity for Thomas to take over and potentially put Boston on the verge of facing the Cleveland Cavaliers in the Eastern Conference final.

“We made quite a few mistakes early,” Brooks said. “We can’t have that. If you do, it’s what you see: a 3, a 3, a drive, a 3, a 3, a drive. You have to be able to execute our game plan, and with that even being said it’s not a guarantee that he’s going to miss shots. … He had wide-open looks and they made an adjustment and I think we did a good job of figuring that out.”

The onus is now on Thomas and the Celtics to adjust back for Game 5 and beyond. He said it was up to his team to make the Wizards pay for giving him so much attention. But he also wants a few whistles.

“I’m just going to keep fighting,” Thomas said. “If they’re going to allow them to be aggressive on me and physical on me, they should allow me to do the same thing back and I felt like (Sunday) I wanted to be physical on the defensive end and I was called for some cheap ones. But there’s no excuse. Just got to figure it out.”