Turner, who has released a number of his senior players from their contracts in the past week, believes that a new "influx of players" will help them in League One next season.
He told the club's official website: "We've had some players who have been with us for several seasons and done extremely well. I'm thinking about Mark Wright with his goals from the wide left position and Matt Richards for the part he played, certainly in the promotion year and the number of games he's played this season.
"It is difficult circumstances but it has to be done. If there's going to be changes you have to be a little bit ruthless about things. What we can do is wish them all the best for the future and I'm sure players like those two will get decent clubs.
"But for us I just felt it was time to move on and we need a fresh influx of players. I think we've got the nucleus of a decent squad, we've got some very promising young players that will get better. It's just adding one or two experienced players to the squad that we've got."
Matt Richards and Marvin Morgan will both depart the club at the end of June.