Keller will have an MRI Saturday night, a league source told ESPN NFL Insider Adam Schefter.
Keller's leg bent unnaturally when he was tackled on the right knee by D.J. Swearinger on an incomplete pass Saturday night. He immediately grabbed his right knee and was soon carted off the field.
The team didn't provide any official word on his injury.
Swearinger took to twitter Sunday to express his regret at Keller's injury.
Everybody pray 4 justin keller....i pray you have a speedy recovery bro...and kill it when you get back.... DEFINITELY wasnt intentional..
— DJ Swearinger (@JungleBoi_Swagg) August 18, 2013
Keller spent his first five seasons with the New York Jets before signing with the Dolphins in the offseason.
He had one reception for 14 yards on Saturday.
Information from ESPN NFL Insider Adam Schefter and The Associated Press was used in this report.