Colchester United manager John Ward has offered trials to Lloyd James, James Walker and Ben Coker during pre-season.
Midfielder James, 22, was released by Southampton at the end of the season and striker Walker, also 22, started the last campaign at Southend.
Winger Coker, meanwhile, impressed in a trial match for Colchester's reserves against Norwich last season.
Ward told the club's official website: "The three lads will be here for a minimum of two weeks and we will be taking them to the first pre-season game against Dover on 10th July and see if we can take it on from there.
"Improving the squad isn't always easy and we will try and improve on our top eight finish.
"What's more, the players that are already here will sit up and take notice when there are a number of new faces here.
"The three lads have got to prove to me they can get in the team. They have good pedigree and have shown a real willingness to come here and give it a go."