"No, I wouldn't kid about something like that," said Gundy. "It is true."
The head coach said that Walsh had to be really tough to do what he did as he played the rest of the Cowboys' 31-10 victory over Iowa State on Saturday.
On the sidelines, he notified the medical staff that his knee was sweeling up and they examined him. But he was able to continue. Walsh wore a sleeve on the right knee in the second half and continued playing.
The redshirt freshman completed 32 of 47 passes for 415 yards with one touchdown and no interceptions against the Cyclones.
The Cowboys have also lost for the season tight end Justin Horton, who was injured in the third quarter. Horton tore his left Achilles tendon on a 24-yard catch.