Spikes is not appealing the four-game suspension, allowing the punishment to begin with Sunday's game against the Chicago Bears at Soldier Field and wiping out the remainder of the regular season. He will be allowed to participate in the playoffs .
"I've been contacted by the NFL and informed that I will be suspended four games for the detection of an illegal substance in a drug test," Spikes said in a statement released by the Patriots. "The substance was a medication that I should have gotten clarification on before taking. It was not a performance enhancer or an illegal drug.
"The integrity of the game is very important to me. I understand the league's ruling and apologize to my teammates, the fans and the Patriots organization for this mistake."
Spikes is second to inside linebacker Jerod Mayo in tackles. Spikes has 71, according to the Patriots' game film. He snagged his first NFL interception Monday night, against the Jets' Mark Sanchez in the red zone.
Gary Guyton likely will replace Spikes in the lineup. Guyton has four starts this season. He has 43 tackles, two sacks, three quarterback hits and an interception that he returned 59 yards for a touchdown.