Mavs-Blazers preview: Luka may return; focus must be high, regardless

During a long season of ups and downs, there are certain games in which championship-level teams need to care of business and deposit wins in the bank.

Monday’s match with the Portland Trail Blazers qualifies in that category.

The Blazers are an improving team, but they aren’t ready to challenge for anything other than possibly the No. 1 lottery pick and the rights to next summer’s top prize, Cooper Flagg.

But the Mavericks are in a stretch of the schedule where they can’t afford any slippage. They had a superb hot streak through November and early December, when they won 11 of 12 games.

But they have only split their last four games and after the Blazers come through, the Mavericks have a…