Diaz, 35, is at the end of a two-year contract he signed with the Pirates before the 2011 season (the Braves acquired him in a trade on Aug. 31 of that year). He said he doesn't want his career to end with an injury and intends to play next season.
"I'm not going out with a splinter," Diaz said. "I'm going to have someone tell me I'm not good enough to play next year before I'm going to quit."
Wednesday's surgery will be performed by Dr. Gary Lourie, who also operated on Diaz's thumb in 2010. Diaz said the procedure will be the same as it was two years ago, only more invasive, so Lourie can make sure all the foreign bodies are removed.
When Diaz had the surgery in 2010, he was trying to get back to action as soon as possible. But with the end of this regular season only six weeks away, returning isn't possible. That gives Lourie the opportunity to make a larger incision without delaying Diaz's return to the field.
"He's going to be able to take his time, look around in there, open it up wider and make sure we've gotten every last piece," Diaz said.
Diaz is hitting .222 with a .280 on-base percentage in 51 games this season. He has mainly provided a right-handed bat off the Braves' bench and backed up the corner outfield spots.
Coming off an injury with subpar numbers, Diaz knows he won't be highly sought after as a free agent. He said his preference would be to remain with the Braves, where he has played seven seasons of his 10-year career.
Diaz said he would be willing to sign a Minor League contract if necessary, but is hopeful he won't have to go back to Triple-A, where he has played 272 games, to revive his career.
"I might be going to try to add on to some of my International League stats, but I want to play baseball again," Diaz said. "I hope not to. It's a great league, don't get me wrong. I've just spent enough time there to have some career marks and I don't want to add to those."
Teddy Cahill is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.