LeBron James
LeBron James had a poor game as the Cavaliers lost Game 1 to the Celtics. Pictured: LeBron James #23 of the Cleveland Cavaliers reacts against the Boston Celtics during the third quarter in Game One of the Eastern Conference Finals of the 2018 NBA Playoffs at TD Garden in Boston, May 13, 2018. Maddie Meyer/Getty Images

LeBron James is confident the Cleveland Cavaliers will get better as the series continues following a heavy 108-83 loss to the Celtics in Game 1 of the Eastern Conference Finals on Sunday at the TD Garden in Boston.

The Cavaliers had time to rest for the first time in the playoffs after sweeping the Toronto Raptors in the semi-finals but found themselves 36-18 behind after the first quarter.

Trailing as much as 29 points during the game, the Cleveland side were never in the game as Jaylen Brown's 23 points, Al Horford's 20 and Marcus Morris' 21 gave the home side a 1-0 lead in the series.

James had his worst game of the postseason so far with 15 points from 5-for-16 shooting as well as seven turnovers while the Cavaliers' 26-point halftime deficit was the largest in the 33-year-old's 229-game postseason career.

In addition, the 25-point loss was the largest Game 1 defeat of any James-led side. Similar to his reaction after their Game 1 loss to the Indiana Pacers in the first round of the playoffs, however, he is still not worried.

"I have zero level of concern at this stage," James said after the game, as quoted on ESPN. "I didn't go to college, so it's not March Madness [where there is no best of seven]. You know, you get better throughout the series. You see ways you can get better throughout the series."

"But I've been down 0-1, I've been down 0-2, I've been down before in the postseason. But for me, there's never no level of concern, no matter how bad I played tonight with seven turnovers, how inefficient I was shooting the ball," he said. "I'm just as confident going into a series whether it's a 0-0 series or I'm down 0-1. So we have another opportunity to be better as a ball club coming in Tuesday night, and we'll see what happens."

A major contributor to the Cavaliers' losing was their three-point shots which were lacking as they missed their first 14 attempts and only finished the game shooting 4-for-26 from beyond the arc. Most worryingly, they only scored one three-pointer out of 12 which were uncontested but given the side's dependency on the shot, James believes they will still play the same way going into Game 2.

"I mean, 3-point shot is a part of our DNA," James explained. "It's what makes us the best team that we can be. I think even early on with the shots that we had, we had some wide-open looks that just didn't go."

"We're going to take those same looks going into Game 2 if the opportunity presents itself. The 3-point shot has been a big part since we pretty much assembled this team four years ago, and I think it's going to be a big part of it throughout the series, as long as we continue to get the ball moving and guys feel in good rhythm," he said.

Game 2 takes place at the TD Garden again as the Cavaliers will look to avoid going 2-0 down in the series.