The team said Dr. Tom Hackett will perform the surgery on Gonzalez to repair his left patella tendon. He is expected to be out for five to six months.
"Of course, this wasn't something that I was looking for, but I know we're looking for results," Gonzalez said to MLB.com. "We're looking to get something done so I don't have to deal with this."
Gonzalez dealt with tendinitis in his left knee for the past year and team had put him on the disabled list last week. He missed 35 games earlier this season after doctors found and removed a small tumor in his left index finger.
Gonzalez hit .238 with 11 homers and 38 RBIs this season for Colorado, who have the worst record in the National League at 47-74.
- Scooby Axson