Weeden, who did not return for the final minutes of Cleveland's 14-6 loss, said that X-rays on his right thumb were negative. The Browns were not certain whether Weeden will play in Week 3 against Minnesota.
"The X-rays were negative, so that's a good thing,"Weeden said. "It only happened an hour ago, so it's hard to figure anything out. We'll know more tomorrow."
Weeden was 21-of-33 for 227 yards and was sacked five times before being pulled. Jason Campbell replaced Weeden but was unable to rally Cleveland past the reigning Super Bowl champions.
Weeden claimed that he suffered the injury when he hit his thumb on another player's helmet. The second-year quarterback said he could not grip the ball, forcing the Browns to turn to Campbell.
"I hit it on a helmet on one of the last plays of that drive," Weeden said. "I found I couldn't grip the ball, so I knew I had to come out.
"It really hurts. It also happened to me once in college when we were playing Washington State."
ESPN.com's Jamison Hensley contributed to this report.