The experienced trio's deals all run out in the summer and the offer was made to each player personally by chairman John Bowler at their Reaseheath training ground.
Boss Dario Gradi recommended the offers be made now so the players did not go into the summer break unclear on their futures and all have gone away to consider their options.
Gradi told the club's official website: "We wanted to do what was best for the players and I think it is a very loyal move from the club because we don't know what league we will be in next season.
"The difference if we go up will be considerable."
