Back spasms being endured by Sam Cassell worsened Saturday night in a 99-86 victory over the Portland Trail Blazers at the Rose Garden.

Cassell, 37, collapsed in the second quarter and did not return. X-rays were negative.

The Clippers planned to schedule an MRI exam today or Monday for Cassell, who probably would be monitored for at least a week before his status is evaluated, team trainer Jasen Powell said.

"I'm going to have to sit down a while and let this heal," Cassell said. "I'm going to need some time, maybe until the playoffs, because I'm hurting right now."