PORTLAND, Ore.  — On the eve before the NBA season begins, Portland Trail Blazers forward Nicolas Batum will undergo surgery on his right shoulder to repair torn cartilage.

After the surgery, Batum may need as much as 4 months to recover.

The injury was originally suffered late last season in a 93-89 loss to the Dallas Mavericks at the Rose Garden.

Batum would finish out the season, but the injury remained.

The 6-8 forward would go on to play for his national team, but Batum’s ailing shoulder gave cause for concern to the Portland Trailblazers, who summoned the 20-year old back to the United States so the Blazers’ doctors could look at the shoulder first hand.

The Trail Blazers open the 2009-10 season at home tonight against Houston Rockets.