Spencer suffered the injury in last week's organized team activities and underwent an MRI afterward.
Spencer said he also has a bone bruise and that he will try to practice Wednesday.
"It could have been a lot worse," said Spencer, who walked around the Cowboys' complex with no limp. "You can't play football without having contact."
Spencer said he suffered the injury when he bumped knees with another player.
Numerous other players missed Tuesday's minicamp practice. Among the notables:
*Tony Romo is out the rest of this week as he recovers from back surgery to remove a cyst. Romo said he's throwing and should be ready for training camp.
*Morris Claiborne missed Tuesday's session with a migraine.
*Joseph Randle won't return to the practice fields until training camp. Randle has a cast on his thumb and it won't be removed until later this summer.
*Lawrence Vickers will miss the veteran minicamp as he recovers from back surgery.
*Nate Livings has a knee injury and should be ready for training camp.
*Mackenzy Bernadeau did some individual work in Tuesday's session and is out of team drills with a shoulder injury.
*Jermey Parnell has a hamstring injury.
*DeMarcus Ware (shoulder) participated in individual drills. He's going to miss the veteran minicamp but should return for training camp.
*Dwayne Harris suffered a sprained right ankle during a running play Tuesday. Harris said he's fine and will try to practice Wednesday.