It was the heart and not the head, the rush and not the rest.

Klay Thompson felt fine in the first game back after suffering a concussion. It was a situation that required him to miss five consecutive days of practice, between time sidelined by league rules for dealing with the injury and the Warriors' own calendar between the end of the Western Conference finals against the Rockets and the start of the championship series with the Cavaliers.

Well, he was fine medically, at least.

His blood was pumping, his heart was racing, his nerves were bouncing off the walls of Oracle Arena on Thursday night in Game 1 more than the blasting crowd noise. That was the problem as Thompson missed five of six shots in the first half and was unable to get to the foul line, part of the game he has taken particular pride in developing this season. He was nervous playing in The Finals for the first time, not woozy or rusty from the layoff.

Despite an off shooting night, Klay Thompson scored 21 points in Game 1.
Ezra Shaw / NBAE via Getty Images

Exactly the development the Warriors wanted, in other words, because he can play through jitters. They know this because he did, taking a deep breath, finding solid ground by halftime, and then making four of eight attempts in the final two quarters and overtime in a finish they hope is a beginning.

If that was the worst of it from Thompson in the series -- out of rhythm from the extended absence from practice, out of sorts from the first time being on this stage, and still able to walk out of the building encouraged -- he'll be just fine. And Thompson's defensive assignment, Kyrie Irving, is now lost for three to four months following a fractured kneecap and subsequent surgery. That makes Thompson's difficult challenge of checking a top offensive threat with the added degree of difficulty of being a shooting guard on a quicker point guard a lot easier.

Thompson is now doubly back, as opposed to just the back of being in uniform for the opener while out of sorts early, and Irving is out. This couldn't have broken much better for the Warriors heading toward Game 2 on Sunday at Oracle.

"We're always looking for that moment where Klay kind of just gets in that crazy zone where he can just get hot really fast," Andre Iguodala, one of the Golden State heroes in the Game 1 victory, said after practice Saturday. "I think in the playoffs we haven't had it yet, but I feel like it's slowly but surely getting there.

Thompson's defense will also be pivotal during the NBA Finals.
Ezra Shaw / NBAE via Getty Images

"What I saw (Klay} do was get to the line, which is key for him and for Steph (Curry). Steph did it in overtime, but once (Thompson) starts understanding that when he's not making shots, get him to the line, get him in a good rhythm, that will really start for him."

That was the other encouraging part about the second half Thursday. After two free throws the first half, Thompson's six attempts in the second and overtime built momentum for Game 2 and beyond as the Warriors prepare for whether LeBron James can take on more responsibility than the 38 shots in the opener to make up for Irving's loss.

"Man, that'd be tough to take more on," Thompson said. "(LeBron) could, though. He's capable of doing it. But I think tomorrow he'll try and get his teammates going. He knows that he can't do it by himself so he's going to obviously try and get as many involved as he can. Like I said, they got guys who are more than capable. You can't take them lightly. They've had many wins this postseason without Kyrie. We've got to just wear on 'em with our depth and our defense."

With Thompson a big part of both. He would have been no matter what, of course, but ending Game 1 on a positive note became the reinforcement of the medical opinion from two days before, when he was cleared to resume practicing.

Thompson was feeling fine. And then he showed he was fine.

"I just felt like I was more patient," he said of the basketball recovery that followed the health recovery. "I was playing my game. I didn't let defenders rush me. I got good shots within the offense and I was aggressive. I was getting to the free-throw line. I was shooting without hesitation."

He was back.