Washington Wizards guard John Wall (2) goes to the basket against Memphis Grizzlies forward Zach Randolph (50) and guard Nick Calathes, right, in the first half of an NBA basketball game, Tuesday, Feb. 11, 2014, in Memphis, Tenn. (AP Photo/Lance Murphey) Washington Wizards guard John Wall (2) goes to the basket against Memphis Grizzlies forward Zach Randolph (50) and guard Nick Calathes, right, in the first half of an NBA basketball game, Tuesday, Feb. 11, 2014, in Memphis, Tenn. (AP Photo/Lance Murphey)

MEMPHIS, Tenn. – John Wall was lagging behind Memphis Grizzlies point guard Nick Calathes when Calathes decided to use teammate Marc Gasol as a shield on the left side of the court to break wide open. When Calathes eased to the basket for an uncontested layup, Wall glared back at Kevin Seraphin, threw up his hands in frustration and shook his head as he dribbled up the court.

Coach Randy Wittman called a timeout to scream at Seraphin for failing to leave his man and moving to protect the rim. Nene gave Seraphin a funny look and pointed at Seraphin when approached by Wizards assistants. Other Wizards teammates also gave Seraphin an earful for missing his assignment.

What got lost in the breakdown — which happened during the Wizards’ 92-89 loss to the Grizzlies on Tuesday night — was that Wall was also culpable. Because even if he had given chase, Seraphin never would’ve been able to catch up to contest the shot because Wall had done so little to keep Calathes in front of him.

Wall would keep his guard down for most of the night as Calathes became the latest point guard understudy to take advantage of an seemingly uninterested Wall and have a star turn. With Mike Conley sitting for the sixth straight game with a sprained right ankle, Calathes filled in and finished with 18 points and a game-high six assists to lead the Grizzlies.

“He’s a solid point guard,” Wall said of Calathes. “Somebody who knows his role and gets his teammates involved, but he had a couple of opportunities to get some easy shots and get himself going, but he did a great job running his team.”

Conley was on the court warming up on his sprained ankle before Tuesday’s game, but keeping him out against the Wizards was arguably the best decision Coach Dave Joerger and his staff made all night. With Calathes on the floor instead of Conley, the Grizzlies had a better chance of catching Wall slipping defensively.

Wall has gotten up for the challenge against some of the NBA’s top point guards this season, including Stephen Curry and Deron Williams. But in recent weeks, he hasn’t been able to summon that same intensity against some unheralded backups, which has come back to hurt the Wizards too often.

When the Boston Celtics came to Washington last month, Rajon Rondo was unable to play as he recovered from a right knee injury and his replacement, Phil Pressey, made five three-pointers — one less than his season total to that point — and scored a career-high 20 points to lead his team to an overtime win.

Chris Paul sat out the Wizards’ last meeting against the Clippers with a shoulder injury, but Darren Collison made sure  Los Angeles didn’t experience much of a drop-off as he finished with 16 points and a game-high nine assists to lead his team to victory.

Tony Parker developed back stiffness and was forced to sit out the entire second half against the Wizards last week, but Patty Mills scored 17 of his 23 points after halftime to carry San Antonio to a 125-118 double-overtime victory.

Wall silenced Reggie Jackson when the Wizards defeated Oklahoma City earlier this month, but only after learning a tough lesson on Nov. 10, when Jackson took over after Russell Westbrook was ejected and led his team back from a 10-point deficit with three minutes left in regulation before Kevin Durant closed.

In his fourth season, Wall has made some major strides to earn his first all-star appearance, but Coach Randy Wittman has repeatedly said that the next stage of his growth is on the defensive end. That sentiment was echoed by Wall’s college coach, John Calipari, who was in attendance for the Wizards’ 93-84 win against Sacramento on Sunday and said before the game that he was most interested in seeing how Wall defends. Kings point guard Isaiah Thomas went off for 30 points.

Without singling out any individual after Tuesday’s loss, Wittman said afterward, “Against a team shorthanded, we don’t respect the game.”

Calathes is a rookie who spent the previous four seasons in Europe after failing to latch on to Minnesota Timberwolves, who drafted him in the second round in 2009. But Calathes got the best of Wall on both ends, as Wall had the worst game of the season.

Wall scored a season-low five points on 2-of-10 shooting from floor and 0 for 4 shooting from long distance, including a bad three-pointer in a failed attempt to tie the score as time expired. He also got four of his five assists during a two-minute stretch in the third quarter. But even more telling of his defensive struggles, Wall didn’t have any steals or blocks and committed four fouls.

“We just didn’t play with enough energy and that starts with me. And if you’re not making shots, you can do other things and we didn’t do that,” Wall said. “I didn’t make shots and I wasn’t aggressive like I usually be on the defensive end.”

The Wizards feed off Wall’s passion on the floor and can also fade on the nights that he doesn’t have it. Trevor Ariza went scoreless in the first half and usually benefits from Wall creating open looks for him. Ariza didn’t have many against the Grizzlies as the Wizards  slumbered through much of the game, settling into Memphis’ desired, grinding tempo.

“It’s something we have to figure out as players. Our coaches prepare us. We just don’t come out with energy certain nights and that hurts us against good teams,” Wall said. “They wanted to play at a slow pace and that’s what they did most of the game.”

Point guard is the toughest position in the league and keeping up with the league’s best will lead to some unfavorable results – Paul and Kyrie Irving have both had great games against Washington.

But just as Wall likes to prove he belongs against more accomplished or decorated competition, he faces players with the same mind-set when going up against him. Being an all-star now means that players will measure their games and make names for themselves against Wall. He simply can’t take a night off.

Wall certainly carries a heavy burden as the Wizards’ primary playmaker and has the ball in his hands for most of the time he’s on the floor. But he had some help against the Grizzlies, with Bradley Beal scoring a career-high 37 points and Nene winning his individual duel against Zach Randolph.

“He had a big game for us,” Wall said of Beal. “It was one of those games where a guy like that keeps you in it but other guys got to step up and make plays down the stretch and make plays…We didn’t put the pressure against them defensively. I think our bigs did a great job on Gasol and Randolph, but the other guys, we just let them do whatever they want freely.”