"Sometimes the season ends like the way the whole season goes," Diaz said. "I don't think it's going to be too serious. I'll let it heal for a couple of weeks and then get back working to get stronger again."
Diaz started the team's final three games at third base, a position at which he gained exposure during his time in Triple-A Memphis. After opening the season as the Cardinals' starting shortstop, Diaz was demoted to the Minors in July and remained there until Memphis' postseason run ended in mid-September.
Diaz finished with a .259/.290/.392 slash line over 301 plate appearances in his second big league season. His OPS dropped nearly 200 points from his All-Star rookie season.
"There was a lot of frustration," he said. "It was a tough season for me. But at the same time, I had a chance to get back here and then work this offseason to get better."
Jenifer Langosch has covered the Cardinals for MLB.com since 2012, and previously covered the Pirates from 2007-11. Follow her on Twitter and Facebook. This story was not subject to the approval of Major League Baseball or its clubs.