LaRon Landry has been suspended for four games for a violation of the NFL's performance enhancing drugs policy.

Landry is the Indianapolis Colts' starting safety.

The Colts signed Dewey McDonald from their practice squad in a related move.

Chris Harris believes Russell Wilson is a better quarterback than Andrew Luck.

Harris and the Denver Broncos have played both Wilson and Luck this season.

"He's the best quarterback we've played so far," Harris said of Wilson. "I don't know why they keep saying Andrew Luck is better than him. He's not better than Russell Wilson."

Luck was taken by the Colts with the No. 1 overall pick of the 2012 draft. Wilson wasn't selected by the Seahawks until the third round in 2012, with the 75th overall pick.

Robert Mathis will miss the rest of the season due to a torn Achilles tendon, a source confirmed to ESPN NFL Insider Adam Schefter.

Mathis, who currently is serving a suspension for violating the NFL's substance-abuse policy, suffered the injury last week while working out, the source confirmed to Schefter.

Mathis' season-ending injury was reported earlier Monday by Pro Football Talk.

Jim Irsay has been suspended six games and fined $500,000 by the NFL after pleading guilty to one misdeameanor county of operating a vehicle while intoxicated.

The suspension takes effect at 5 p.m. ET on Wednesday, and Irsay will be eligible to return after the Indianapolis Colts' game against the Houston Texans on Oct. 9.

The 55-year-old Irsay admitted to a judge he was under the influence of the painkillers oxycodone and hydrocodone when he was arrested on March 16 near his home in the Indianapolis suburb of Carmel.