BROOKLYN -- The running, gunning, happy-go-lucky Los Angeles Lakers have disappeared. They are winless in December, and, after their latest loss, the most mellow coach in the NBA lost his cool.

"[Luke Walton] just challenged us," Lakers forward Larry Nance said following their 107-97 loss to the Brooklyn Nets on Wednesday. "He said we're mentally weak, we gotta bring it. He challenged us as men, as basketball players."

Walton, described by guard D'Angelo Russell as "a big brother figure" during training camp, can be hard to hear in media scrums from just a few feet away. He has been earned praise for getting away from former Lakers coach Byron Scott's old-school, tough-love approach and empowering his young players. It is difficult to imagine Walton sending a strongly-worded email, let alone ripping into his team, but Los Angeles guard Nick Young said the 36-year-old coach raised his voice and got his point across.

Walton's point, according to Young: "Just mentally being soft. Calling us out. We gotta step up to the plate. I know I'm not soft. My teammates are not soft. So we gotta show it and prove ourselves."

"It's true," Nance said. "We've been getting mentally outworked. We've just been, a lack of focus, knowing our personnel, there's been a lot of issues we've had. I think the resiliency we're lacking is due to a weakness mentally. So I think he's right."

Luke Walton upset in Brooklyn
Luke Walton says the Lakers don't understand how hard it is to win. USATSI

During the Lakers' 7-5 start, their defense could come and go, but they never stopped attacking or competing. A month ago, they had the league's ninth best offensive rating and 19th-best defensive rating. Now they're 20th and 30th, respectively, with an eight-game losing streak. Young said they've been "folding" and that their coach "believes too much in us for us to go out like this."

Part of their slide can be attributed to injuries. Russell missed most of the last month, and Young was out for two weeks. Since they've returned, though, Los Angeles has not recaptured its early-season magic.

"The losses, obviously, they hurt, they're frustrating, but it's the fact that we haven't found our way again since the injuries hit," Walton said. "Now that we have guys back, we're still playing without a purpose for too much of the game."

There were a couple of Showtime moments at Barclays Center. In a span of 18 seconds in the third quarter, Young swished a 3-pointer, Nance got a steal and Young threw down a dunk on a fast break, eliciting oohs and ahhs from the considerable number of Lakers fans in attendance. A few minutes later, everyone in the arena lost their collective minds, as Nance drove to the basket, took off from the dotted line, climbed Brook Lopez, extended his right arm skyward and flushed the nastiest dunk the NBA has seen in some time. Despite the energy from the fans in the building, the Lakers could never muster much momentum.

"Little moments in the game that I felt we really could have got some distance, we casually approached," Walton said. "As a group, as a team, we got a lot to learn about winning and how hard it is. It's frustrating, but it's where we're at. It's like I told the guys, we're going to find a way out. When that is, time will tell."

Brooklyn managed to beat the Lakers despite only shooting 38.4 percent. Walton had a list of grievances -- free-throw shooting (Los Angeles went 21-for-34), a lack of communication on defense reverting to individualistic play when open shots weren't falling -- but nothing bothered him more than their lack of effort on the defensive boards. Nets forward Trevor Booker pulled down 18 rebounds, five of them on the offensive glass.

"He plays hard, he's a talented player, he's great at what he does, but he's an undersized 4 -- he got 18 rebounds," Walton said. "When you're serious about stopping the bleeding, you get in there, you mix it up, you don't let someone who gets rebounds by outworking people get 18 of them. There's a lot we can fix."

Earlier in the year, Los Angeles was the type of team that was hard not to root for. After a miserable 2015-16 season, the young guys were enthusiastic and had an edge to them. Now that the Lakers have lost some of that luster, Young said they have to "find that chemistry again." A little adversity isn't always a bad thing, especially for a developing group, but it's not a ton of fun when you're in the middle of it.

"We've just got to go back to the drawing board," Nance said. "We gotta figure something out and get on top of it before it compounds even worse."