Colchester United defender Matt Heath has signed a new one-year deal, while winger Simon Hackney will be released when his contract expires this summer.
Former Leeds centre-half Heath, 30, has featured 29 times for the League One U's this season.
He joined the club in May 2008 after an initial loan spell and has made 74 appearances in total.
"It's nice for me to stay at the club I've been at for three and a bit seasons," he told BBC Essex.
"I'm very happy and settled in the area as well.
"There's a lot of positives from the season, the main thing is our home form and if we can build on that next season hopefully we can scrape into the play-offs."
Hackney, 27, played 13 games during a loan spell for Oxford this season, but that was cut short by injury.
He made 41 appearances for Colchester since he arrived from Carlisle in 2009.