But he knows he can't redo the situation. That's why he's accepted his four-game suspension for violating the league's drug policy.
"It's been a long process," Mathis said at the team's facility Wednesday. "It kind of ran its course, and all I could do is accept it."
The suspension has taken several twists and turns since it was announced by the NFL on May 16.
The pass-rush specialist used the drug Clomid, which is prohibited by the league, with the sole purpose of helping him and his wife have a baby. Mathis claims he relied on an urologist's advice on taking the drug.
Steven Morganstern, the urologist who prescribed the drug, told ESPN earlier this week that Mathis took the drug only for fertility purposes.
Morganstern also said he didn't know Mathis was an NFL player.
"The first principle of our joint drug program with the players' association is, you're responsible for what's in your body," NFL commissioner Roger Goodell said at the league's owners meetings Tuesday in Atlanta. "There are several avenues for you to contact people in advance to determine whether you should or should not take a particular drug. And we have a process set up."
Mathis, who led the league in sacks last season with 19.5, met with his teammates recently and told them, "Sorry, and I'll be back."
He is allowed to participate in all offseason workouts as well as preseason practices and games while suspended. He'll miss the Colts' first four regular-season games and is eligible to return the day after the Sept. 28 game against Tennessee.
"Even more motivation," Mathis said. "I know how hard the team works, and I know how hard I work personally. Being motivated is not an issue. I just can't wait to get back."
Colts LB Mathis Regrets Decision, Accepts Ban
Antonio Pierce discusses why an NFL protocol to protect players from taking banned substances wouldn't necessarily be effective.