League Two Doncaster Rovers sign teenage defender Tyler Garrett from Bolton Wanderers as Richard Chaplow departs.
Chesterfield goalkeeper Tommy Lee could miss the start of the League One season after suffering a shoulder injury.
Colchester sign Birmingham's Denny Johnstone for an undisclosed fee and Brentford's Courtney Senior on a free transfer.
Portsmouth sign Milan Lalkovic from Walsall after the two clubs reached a compensation agreement.
Port Vale make their first summer signing, Dutch defender Kjell Knops from Eerste Divisie side MVV Maastricht.
Defender George Williams will re-join MK Dons on a two-year deal on 1 July when his Barnsley contract ends.
Defender Damien McCrory commits his future to Burton Albion by signing a new two-year deal.
Former Norwich City striker Grant Holt is training with Hibernian after the 35-year-old was released by Rochdale.