Perhaps Brett Brown believes that the only people standing in the 76ers' quest for a top-four playoff seed are the Sixers.

"We [had] a meeting today. Coach was talking about [how] we have to be more of a playoff mind, more ready to play playoff defense," Dario Saric said after Monday's shootaround at the team's practice facility.

Brown is a little disappointed that the Sixers were fifth in surrendering points per 100 possessions at 103.3 as of Sunday. They were third a month ago.

"Nothing matters unless we play defense," Brown said. "That's how we have set the tone of this program since the day I arrived."

The coach doesn't like what he's seen from his defense since the all-star break.

"I especially didn't like what I saw the past two games [heading into Monday's game against Charlotte]," he said.

The Sixers had subpar performances against struggling Brooklyn and New York. They ended up trailing both squads by double digits and needed late runs to escape with victories. That's not the type of performance expected from a squad determined to get a top-four seed.

"We managed to find ways to execute and guard in the fourth period," Brown said. "But to arrive at the point, I think that our defense has been watered down. And it can't. The sting to our defense is Philly hard, Philly edge. That stuff matters."

The Sixers are sixth in the Eastern Conference, one game behind the fourth-place Washington Wizards, with 14 regular-season games remaining. The top eight teams at season's end will advance to the postseason, with the top four getting home advantage in the first round.

"It can only happen if we guard," Brown said.

The Nets and Knicks are the type of opponents the Sixers should blow out.

"You can see in the last two games against New York and Brooklyn, it wasn't us," Saric said.

He added that the Sixers need to be mentally ready, especially since it's late in the season.

Ben Simmons said he was dealing with mental fatigue against the Nets.

"It's just frustrating," he said."Missing plays or just messing up on the floor, turnovers, rebounds that you should've gotten," he said, "It's just the little things that kind of get under your skin.

"I'd say watching film you kind of see it a lot more."

Simmons has "no idea" why the Sixers weren't at their best against Brooklyn. He said it could be the mental fatigue.

"It also could be knowing it's Brooklyn, not a team that up there [in the playoff race]," Simmons said. "That could be part of it."

The schedule is set up for them to accomplish their goal of getting a top-four seed. Nine of the 14 games will be at home. The Sixers will play four teams with winning records — Minnesota (Saturday), Denver (March 26), Cleveland (April 6), and Milwaukee (April 11) — with all four games at the Wells Fargo.

The 14 remaining opponents had, through Saturday, a .404 winning percentage, giving the Sixers the easiest schedule in the NBA the rest of the way. The third-place Cavaliers (40-29), who are 1 ½ games ahead of the Sixers, will play teams with a .483 winning percentage, followed by Washington (.491), and No. 5 Indiana (.551, the sixth-toughest). The Wizards and Pacers, both at 40-30, are a game ahead of the Sixers.

"Every game is important," Saric said. "Coaches have a made point [of telling us], put everything on the court."