And Dirk Nowitzki recognized it.
"You know, Portland and L.A. obviously are bigger teams, and now we're facing a different animal," Nowitzki said. "We're facing athletes on the wing, and we're having a tough time getting some stops."
It's clear that too much attention -- as Mavericks coach Rick Carlisle contended before the series -- was being paid to Dallas' experience versus the youthful Thunder's lack of it as the ultimate difference-maker. It didn't matter Thursday night, as Oklahoma City's exuberant and athletic lineup dominated the fourth quarter then managed to hold off a late Dallas charge.
The Mavs, collectively a decade older than their Western Conference finals counterparts, got slapped back to Earth after seven consecutive playoff wins by an explosive offensive team.
"They're a team that, overall, they're quicker than we are," Carlisle said. "So we are just going to have to be more resourceful."
With Games 3 and 4 slated north of the Red River starting Saturday at the Oklahoma City Arena, where the home team can generate offense at a lightning pace, the Mavs must find ways to neutralize the Thunder's quickness or risk being run out of the gym.
That's one issue. But is there a larger internal issue at work that must be nipped?
Inexplicably, the Mavs' mindset going into and during Game 2, after a relatively easy win in Game 1, was being questioned within the locker room following the disappointing home loss, their first of this postseason.
Tyson Chandler said Dallas took the Thunder lightly, and Jason Kidd brought up another disturbing aspect -- but a recurring one during the regular season -- that seems mind-boggling at this stage with the stakes at an all-time high for Dallas' cadre of ring-less vets.
"I think there were stretches during the game where we relaxed," Kidd said. "And again, when you relax against a talented group like that they're going to make you pay for it and that's what they did."
Relaxed? Dallas came out smoking Thursday and led 28-17 as the American Airlines Center roof was about to blow. Instead of the inexperienced Thunder caving, the Mavs let up and eventually trailed by 10 with 3:15 to go.
"I feel like we have got to play with a greater edge for sure," Carlisle said. "I don't think we've lost it, but I think we've got to play with more of an edge."
Dallas' passivity got it outworked and outplayed. Carlisle hammered that point home, especially in regard to his pet peeve of losing the loose-ball battle, a hustle category that can shift momentum and alter the course of a game. OKC coach Scott Brooks recognized the unrelenting energy of his team.
"Like I told the guys before the game, playing perfect is impossible, but playing hard is possible," Brooks said. "You can do that. You can do that every possession, and I thought we did that in the second half. And that's what it's about."
The Trail Blazers and Lakers, with their plodding point guards and more veteran, less athletic rosters, now look to have been the most favorable matchups for an older team such as Dallas. And why, in retrospect, the more physical, front-line driven, defensive-minded Memphis Grizzlies might have actually been the better draw in this round.
This isn't the NFL, but in this series the same principle prevails: You can't coach speed.
Consider that the Thunder have scored 218 points in the first two games on an astounding 51.4 percent shooting, including 55.7 percent in Game 2.
The Lakers, with a jump-shooting Kobe Bryant and an emotionally wrecked Pau Gasol, scored 259 points in the final three games of the second-round sweep. Portland, a bottom-seven scoring team during the regular season, managed 254 points combined in three of the six games. Dallas never surrendered 100 points to either team and entered the West finals second in the playoffs behind the Chicago Bulls, allowing a tick over 88 points a game.
The Thunder ranked third in the league in scoring in the regular season and are averaging 103.8 points a game in the playoffs, a time in which defenses typically buckle down.
"They're a little more athletic, a little quicker, especially on the perimeter, and they've got some scorers there on the perimeter that are tough and can play off the dribble and can break you down," Nowitzki said. "They're always on the move getting screens, moving, and they play well off each other. They're an athletic team, and they did a good job."
This is the first taste of adversity for the Mavs since the unforgettable collapse in Game 4 in Portland. The Mavs responded positively. This hurdle is different. Not only are they coming off a loss, but for the first time in any series they don't have a cut-and-dried answer for the Thunder's greatest weapon.
"Every series is different, but we knew that coming into the series. There's no surprises," Chandler said. "It's just about us forcing our will on them. They're athletic, but we've got to force our will on them."
Jeff Caplan covers the Mavericks for ESPNDallas.com.