Oklahoma City. Indiana guard Tyrese Haliburton grabbed at his lower right leg after an awkward fall in the first quarter of Game 5 of the NBA Finals, briefly leaving the game for treatment.

He returned but it was clear he wasn’t at full strength.

To his credit, Haliburton played through 34 minutes, mostly serving as a facilitating decoy in the second half and rarely looking to score. He finished with just four points, all from the free-throw line, as the Pacers fell to the Oklahoma City Thunder 120-109 on Monday night, slipping behind 3-2 in the best-of-seven series.

“If I can walk, then I want to play,” Haliburton said.

He was scoreless at halftime for the first time in his 36 career playoff games. His first points came on a pair of free throws with 7:07 left in the third quarter.

Now, the Pacers face an even greater challenge in their quest for an NBA title. They’re trailing and their floor leader is hurting.

“We were concerned at halftime, and he insisted on playing,” Pacers coach Rick Carlisle said. “I thought he made a lot of really good things happen in the second half. But he’s not 100%. There are a lot of guys in the series that aren’t.”

It’s the first time Indiana has trailed in a playoff series this postseason. The Pacers never trailed against Milwaukee in the first round, Cleveland in the second, or New York in the Eastern Conference finals.

Oklahoma City’s Game 5 victory also marked the first time Indiana has lost back-to-back games since mid-March. The Pacers had won 10 straight games following losses heading into Monday.

The math is now simple: Indiana must win at home on Thursday to force a Game 7 and then win again in Oklahoma City on Sunday night to secure the franchise’s first NBA championship.

Carlisle said the team will monitor Haliburton over the next couple of days, but his intent to play appears clear.

“It’s the Finals, man,” Haliburton said. “I’ve worked my whole life to be here, and I want to be able to compete and help my teammates any way I can. … It’s not really a thought of mine to not play.”

Haliburton played 10:04 in the first quarter before heading to the locker room. He returned with a wrap on his lower leg and checked back in with 8:27 remaining in the second quarter.

The injury --the specifics of which remain unclear-- has lingered throughout the series. Haliburton was noticeably limping after Game 2 and downplayed the issue before Game 3, calling it “just a lower leg thing.”

On Monday, he added seven rebounds and six assists but missed all six of his field-goal attempts.

“He’s a fighter,” Pacers forward Pascal Siakam said. “He’s been our rock all year. He’s a big reason why we’re here. I don’t know exactly what’s wrong, but I know he’s fighting and he’s going to give us everything he’s got.”