Heading into Saturday night's NBA Summer League matchup, the Philadelphia 76ers were coming off of an impressive overtime win against the Atlanta Hawks. By forming a second-half comeback and forcing overtime, Tyrese Maxey and the Sixers managed to improve to 2-0 with victories over the Dallas Mavericks and the Hawks through their first two Summer League games.

With a matchup against the Boston Celtics approaching on Saturday evening, the Sixers' starting lineup saw a bit of a shakeup. Tyrese Maxey, who led not only the Sixers but the entire NBA Summer League in scoring through the first couple of games, was ruled out for Saturday's matchup.

According to a team official, Maxey's absence was pre-approved by the Sixers. As the second-year guard was set to host a basketball camp in his hometown of Garland, Texas, this weekend, Maxey got the green light to leave Las Vegas prematurely.

Former NBA G League Ignite point guard Daishen Nix backed Maxey at the point guard position through the first two games. However, Nix didn't get the nod to start in Maxey's place on Saturday against the Celtics. Instead, it was veteran guard Frank Mason III who took over and ran the offense.

Mason missed the Sixers' first two games due to a minor injury. As he was cleared for action on Saturday, the 27-year-old ball-handler picked up his first 23 minutes of the summer. Unfortunately, the rust showed for Mason -- and the growing pains of playing without Maxey were real for the Summer Sixers against the Cs.

Personally, Mason shot 4-10 from the field on Saturday night. He also went without draining any of his three three-point attempts as well. In total, Mason collected nine points in Philly's 100-80 blowout loss to Boston. 

Following the game, Sixers head coach Brian Adams and a few members of the roster acknowledged Maxey's absence as a primary reason why they fell short to the Celtics on Saturday. As Maxey's practiced with them, running the offense for the last couple of weeks, it was a tough adjustment going from playing with the standout to playing with Mason, who hasn't been able to make his 2021 Summer League debut until Saturday.

Mason and the Sixers will get an opportunity to bounce back on Sunday. With a back-to-back matchup scheduled against the Minnesota Timberwolves on Sunday night, the Sixers will again take the court without Maxey. Now that they've had some time to adjust to life without the former first-rounder, the Sixers will look for better results against the T'Wolves on Sunday.

Justin Grasso covers the Philadelphia 76ers for Sports Illustrated. You can follow him for live updates on Twitter: @JGrasso_.