They didn't need to watch Doncic's 42-point Game 1 outing, the highest-scoring playoff debut in NBA history, against the heavily favored LA Clippers.
They didn't need to witness Doncic put the exclamation point on a 43-point triple-double with a buzzer-beater to win Game 4 in overtime -- on a sprained left ankle that put his availability in question that afternoon.
And they didn't need to see him battle to the end, totaling 38 points, 9 rebounds and 9 assists in a hard-fought 111-97 Game 6 elimination loss on Sunday without the team's second-best player, Kristaps Porzingis.
If there were any lingering doubts about Doncic's potential to be a dominant force in the NBA for years to come, they were squashed in the playoffs.
"He's a guy that I predict is going to win multiple MVPs," an Eastern Conference scout said. "I could not be higher on a guy in the league. If you start that 'Who would you take to build a team' conversation, there's not another guy that I would take over Luka."
The greatness of Doncic presents an opportunity for Dallas to begin an era as perennial title contenders -- sooner than many expected.
"They're probably closer than even they thought just because of Luka," a West executive said. "He just seems to be a generational talent that can carry a franchise."
The Mavs' goal in the fall was to make the playoffs, which seemed ambitious at the time for a young team in the loaded Western Conference. They accomplished that with Doncic running the most efficient offense in NBA history, although the Mavs' inexperience showed as they struggled to close out games. They ended up seventh in the West and made significant strides this season before bowing out in a competitive series with the Clippers, one of the few teams perceived to have legitimate title hopes.
"He's very poised," Clippers forward Kawhi Leonard said after Game 1. "He's very trusted on that team. He can get to his spots, find his teammates, gets them easy baskets. He makes tough baskets well. He's a great player."
So what is the ceiling for this team next season, with a roster expected to remain largely the same? That might depend on Doncic's sidekick, Porzingis, and his questionable health.
The 7-foot-3 center missed the final three games of the Mavs' series against the Clippers because of a lateral meniscus tear in his right knee, which could need to be surgically repaired. Porzingis also was out for 10 games in the middle of the season because of right knee soreness. That's after sitting out a season and a half following a tear of the ACL in his left knee in February 2018 -- a year before the Mavs acquired him from the New York Knicks in what has been widely perceived as a steal.
The biggest question opposing executives, scouts and coaches have about the Mavs is Porzingis, and whether he can be a championship-caliber sidekick for Doncic. As of now, there is no consensus.
Even when healthy, Porzingis has yet to prove that he can consistently perform at a superstar level despite the unique combination of height, skill and athleticism that earned him "The Unicorn" nickname. His doubters acknowledge, though, that Porzingis got better as his first season in Dallas progressed, particularly after he moved to center full-time in late January.
In his last 21 regular-season games, Porzingis averaged 26.7 points, 10.5 rebounds and 2.1 blocks, the sort of production that hints at his potential as an elite second option.
"I think it's a bit early to make that judgment," a West executive said. "We need to see what happens in the next year with him, but my gut tells me he's going to be a legit No. 2 guy. But it's hard to be that guy when you're sitting on the bench."
Added a West scout: "There's some optimism there. Give the Mavs credit. They went and got a 1 and potentially a 2. Doncic is definitely a 1. I'm not all-in on Porzingis as a 2, but he's a really good 3 in the worst case. Now it's just about filling in the pieces around them."
Whether Porzingis can take that step next season, the Mavs have Doncic, a superstar with prodigious gifts as a passer. And that gives the Mavs, who have planned to be positioned to create a maximum-salary slot to target 2021 free agents, reason for all sorts of optimism in team building.
"They're probably closer than even they thought just because of Luka. He just seems to be a generational talent that can carry a franchise." A West executive, on the Mavericks' championship window
"We're so fortunate to have him," Mavs coach Rick Carlisle said Sunday after Game 6. "Now we've got to get our roster completely healthy and keep working to get the right players around him."
Sources said the Mavs aren't likely to make major roster changes right away, especially if Tim Hardaway Jr. picks up his $19 million player option as anticipated. One path for this offseason being pushed within the organization is to target veterans who have earned reputations for toughness and could be signed to short-term deals.
A member of the front office noted the Mavs must upgrade a mediocre defense -- 18th in the league during the regular season -- to have legitimate title hopes even with a historically efficient offense.
There is some internal hope that the Mavs' young core -- which includes undrafted developmental success stories Dorian Finney-Smith and Maxi Kleber -- can develop enough for the team to become a contender sooner rather than later.
"It's not an easy road," Porzingis said earlier in the series. "Obviously, it takes a lot of experience. I haven't seen a team that it's smooth sailing all the way. ... I believe we're heading in the right direction."
It will also be the last time for a long while that a first-round exit isn't seen as a major disappointment. Teams that feature an MVP candidate and a max-salary sidekick are expected to make deep playoff runs. At some point, satisfaction comes only when a championship parade is scheduled.
"My goal at the start of every season is to win a championship," Doncic, who won titles with Real Madrid and the Slovenian national team, said Sunday. "There's no other hope."
The development and durability of Porzingis could determine if and when. But Doncic has lifted Dallas into the conversation well ahead of schedule.