Both will spend the rest of this season watching from the sideline.
One day after Powers and cornerback Terrence Johnson were placed on injured reserve, Nevis, a rookie, joined the same list Tuesday.
"It's tough, man, it's been a tough year all around for us," Indianapolis safety Antoine Bethea said after learning about Nevis during a charity event.
The decision means two of Indy's top three draft picks, Nevis and offensive tackle Ben Ijalana (knee), have landed on season-ending injured reserve. Nevis played in only five games and had 19 tackles after being selected in the third round out of LSU. Ijalana was a second-round pick from Villanova. Left tackle Anthony Castonzo also missed four games with a sprained left ankle earlier this season.
Losing Nevis makes the Colts (0-12) even thinner along an already depleted defensive line, but the loss of Powers may prove more debilitating.
He was the best cover cornerback on the league's No. 22-ranked pass defense. Powers led the team with two interceptions and had scored one of the Colts' few touchdowns. But when he landed awkwardly while trying to break up a pass in the end zone during Sunday's 31-24 loss at New England, Powers' left elbow popped out of place. He said the elbow was sore and back in place Tuesday night, and said he probably could have been back on the field within three weeks.
The problem: Team officials had so many other roster spots to fill and they couldn't afford to wait for Powers and put him on injured reserve for the second straight season.
Also on Tuesday, the Colts signed defensive back Brandon King from the Miami Dolphins practice squad, claimed linebacker Kevin Bentley off waivers from Jacksonville, promoted defensive back Mike Holmes from the practice squad to the active roster and re-signed offensive tackle Mike Tepper to the practice squad.
Copyright 2011 by The Associated Press