Nowitzki continues to poke fun at deteriorating mobility

Dirk Nowitzki may have lost a step, but he still has jokes.

The Dallas Mavericks star turns 39 in June, and it's become obvious he's not the same player he's been over the past two decades.

He logged 30 minutes in Tuesday's loss to the Portland Trail Blazers, and one observer took to Twitter to comment on how the lumbering big man moves.

Instead of denying his increasing lack of mobility, Nowitzki piled on.

Related: Nowitzki says he runs like he's stuck in 'full on dry cement'

The veteran registered 25 points, five boards, three assists, and two blocks.

Not bad for a geezer.