A tough adjustment

David Stern’s age requirement and Adam Morrison’s poor shooting percentage have conspired to give the NBA the worst rookie class of all time.

The commissioner’s new rule kept high school players out of the draft last year for the first time in Kevin Garnett’s lifetime, temporarily keeping talents like Greg Oden, Kevin Durant and Brandan Wright out of the league.

Morrison, the rare great college player who stayed in school four years, was supposed to enter the league as a polished player. Instead, he’s rusty, shooting 36.9 percent for the Charlotte Bobcats.

(Morrison’s “Halo” rival, J.J. Redick, is averaging 4.4 points in eight games for the Orlando Magic.)

Morrison and Brandon Roy of the Portland Trail Blazers lead all rookies with 13.7 points a game. No. 1 draft pick Andrea Bargnani (10.0 points) of the Toronto Raptors is the only other rookie averaging double figures.

Roy’s modest competition for the NBA Rookie of the Year Award is Raptors forward Jorge Garbajosa (9.2 points, 5.8 rebounds) and Hawks forward Shelden Williams (6.4 points, 6.3 rebounds).

The winner may want to accept the award with a bag over his head.

This season’s winner also may receive another dubious honor — worst rookie of the year ever.

Mike Miller, the 2001 winner after averaging 11.9 points and 4.0 rebounds, currently holds that distinction.

Jazz forward Paul Milsap, Timberwolves forward Craig Smith and Kyle Lowry and Alexander Johnson of the Grizzlies have been the most productive rookies on a per-minute basis, but all of them play less than 20 minutes a game.

Lowry (who is out indefinitely with a broken left wrist), Johnson and rookie teammate Rudy Gay should receive more minutes now that the Grizzlies have conceded the season and director of player personnel Tony Barone is their interim coach.

Of course, there is another option for the NBA Rookie of the Year Award — leave it vacant.