The Dallas Mavericks entered Sunday in control of their destiny for the Western Conference's No. 5 seed. Now a loss Monday night could drop them all the way into eighth - and still not secure of getting in.
The Mavericks and Utah Jazz are separated by one game heading into a crucial meeting in Salt Lake City with plenty on the line for both.
Dallas (41-39) saw its second six-game win streak end while missing a chance to clinch a berth with Sunday's 98-91 loss to the Los Angeles Clippers. The Mavericks fell one game behind sixth-place Memphis and 1 1/2 behind fifth-place Portland.
They no doubt would like to finish fifth or sixth to avoid powerhouses Golden State and San Antonio in the first round. Utah (40-40) will gladly take a matchup with either of those teams since its postseason fate is far from secure.
The Jazz lead Houston by one game for the eighth and final spot, but the Rockets have the tiebreaker and matchups left with lowly Minnesota and Sacramento.
Utah will move into the seventh seed with a victory Monday since it has split its first two meetings with Dallas with this one determining the tiebreaker.
''I don't have to talk a whole lot about it,'' coach Quin Snyder said of the importance of Monday. ''It speaks for itself."
The Mavericks played Sunday without J.J. Barea, who is out with a right groin strain. Deron Williams returned from an eight-game absence due to a left abdominal strain and had 15 points in 28 minutes.
''He was aggressive, especially in the first half,'' forward Dirk Nowitzki said. ''I liked how he pushed it on the break and tried to get into the lane and collapse the defense. When a guy comes back from injury you look how he moves, and I thought he looked great."
Williams will play at Utah for the fourth time since he was traded to New Jersey in 2010-11. He averaged 18.7 points and 7.7 assists while shooting 34.1 percent in the first three games back, getting booed loudly on each occasion.
Jazz forward Derrick Favors, acquired in the trade for Williams, is uncertain after he was a late scratch because of right knee soreness for Sunday's 100-84 victory at Denver. Rookie Trey Lyles, who didn't find out he was starting in Favors' place until moments before the opening tip, scored a season-high 22 points.
''That's the thing about this team. It's been happening all year,'' Snyder said. ''Individually, we've got guys that have depth of character. And then when you put them together collectively, they've been pulling together all year. It was good to see.''
Gordon Hayward also scored 22 and Rudy Gobert finished with 16 points, 14 rebounds and six blocked shots.
It'll be hard for Monday's game to match the drama from the last time these teams met. Hayward hit a winning jumper at the overtime buzzer in a 121-119 victory Feb. 9, with Rodney Hood tying the game with a 3-pointer in the closing seconds of regulation en route to a 29-point performance.
Williams had 23 points and eight assists in the Mavs' 102-93 win over Utah on Nov. 20. The first two meetings were both in Dallas.