NFL teams have until this evening to make their final cuts ahead of the 2013 NFL season.
The head coach told the Colts' website: "It's really tough because over a short period of time, it doesn't take long to build relationships with all these players. Coaches do. Players in the locker room, they become their family.
"It's extremely hard, and it's an opportunity of a lifetime for a lot of them. They've probably been dreaming about this opportunity their whole life. For some of them, they're going to get some disappointing news.
"Everybody's going to have to give disappointing news across the league over the next [few hours]. Does that mean their NFL career and the dream is over? No. What you put out on the field the last three weeks, you're not only trying to make our club, you're trying to make 31 other clubs. Everyone is being evaluated."
The Colts play the Oakland Raiders in the first week of the regular season.