"Christian's more of an offensive option and Nix is more of a defensive option. Breaking it down and looking at all of our scenarios, especially in the National League, we decided to go with the defensive option," Royals manager Ned Yost said before Tuesday's opener.
"We're more apt to probably double switch in some spots, and you quite frankly like Nix's defense a little better at third. Nix and Colon are very solid second basemen. They both play a solid short, but we just felt a little more comfortable with Nix at third."
The 32-year-old Nix hasn't played since the wild-card playoff win over Oakland on Sept. 30, when he entered in the 10th inning and struck out in the 11th.
Colon sacrificed as a pinch hitter in the 10th inning of that game, then drove in the tying run with an infield single on a 12th-inning chopper as the Royals rallied to win 9-8. Colon's only other postseason appearance was when he entered Game 2 of the AL Championship Series as a ninth-inning defensive replacement.
Kansas City is the eighth major league team for Nix and third this season. He started spring training with Tampa Bay, was purchased by Philadelphia on March 28, became a free agent on May 13 when he refused a minor league assignment and re-signed with the Rays four days later.
He played 54 games at the Rays' Triple-A Durham farm team, was released by Tampa Bay on Aug. 1, signed with Pittsburgh two days later and was selected by the Royals off waivers on Aug. 28.