Patton is expected to return to Melbourne on Friday to consult with world-renowned knee surgeon Professor Julian Feller, who performed the young forward's first knee reconstruction.
He could also have surgery in Sydney with Dr David Parker, with the club and Patton currently discussing the 21-year-old's options.
Larkins said Patton's options were limited because of the surgery he underwent in Sweden early in 2012 to treat patellar tendinopathy (also known as jumper's knee).
Patton then tore the anterior cruciate ligament in his right knee during round three last season and missed the rest of the year.
"The choice for him is to have another hamstring [taken from] the opposite knee, so you take good hamstring tissue out of the left knee," Larkins told AFL.com.au.
"Because he's had patella tendon issues you don't want to take patella tendon from his knee because it's not a healthy tendon, and he's already had the right hamstring taken out.
"It's not good going forward. He's a big guy and we hope that he makes a full recovery. We always hope that after ACLs.
"But for a young guy who we haven't seen the best of, it's not great news."
Speaking on Monday, GWS coach Leon Cameron said the club had made contact with Feller and Patton was ready to have surgery either on Friday or Monday next week.
"We're ready to hit it straight away," Cameron said.
