Dr. David Porter was scheduled to perform Nelson's surgery Tuesday in Indianapolis. Porter performed surgery on Wentz's left foot Monday.
"Where Carson's was an old [high school football] injury that cropped up, Q's was not an old injury," Colts head coach Frank Reich told reporters. "Q's was a developmental anomaly. Something he was kind of born with, something always there, you never know and all of a sudden there it is.
"They got there different ways, but essentially the same thing. Can't make that up, right?"
Nelson sustained the right foot injury during Monday's training camp practice. He briefly exited the practice, but he later returned. The All-Pro guard watched Tuesday's practice from the sideline with a boot on his injured foot.
Reich said the recovery timelines for Nelson and Wentz are wide and uncertain because players heal at different rates. The team could have a better understanding on their returns once they begin the rehabilitation process.
The loss of Nelson adds to the Colts' growing list of offensive line problems. The club is already without Pro Bowl center Ryan Kelly for multiple weeks due to an elbow injury, and left tackle Eric Fisher is still rehabilitating from a torn Achilles.
The Colts selected Nelson with the No. 6 overall pick in the 2018 NFL Draft out of Notre Dame. He has started all 48 regular-season games and three playoff contests at left guard since entering the league.
Nelson has been named a Pro Bowler and All-Pro in each of his three seasons.