Tsonga hurt the little finger on his dominant hand when he slipped and fell during the sixth game of the final set.
"I think it's serious," Tsonga said. "I just fell down. That's it. I didn't do, you know, an exam for the moment, but it sounds very bad. I felt like I broke something or I stretched, you know, a lot of ligaments, I would say."
Querrey, who beat fellow American Mardy Fish in the 2010 final, earned a decisive break to lead 5-3 in the final set and served out the match to love.
"I'm feeling really good," said Querrey, who was still on the comeback trail after elbow surgery one year ago. "I have been feeling better every week this year, and my serve is feeling great. I've only dropped serve once so far in three matches.
"Return game is feeling good. Yeah, that's the first time I have won three matches in a row in a while. Just feeling really confident."