Kamara made one first-team appearance last season in a League Cup loss at Sheffield Wednesday before joining Southend United on loan.
Rotherham have signed Chelsea forward Izzy Brown on a season-long loan, while Jamal Blackman has moved to Wycombe until January.
The Premier League, Football Association and English Football League are seeking to address indiscipline in the game by reinforcing laws.
The Football League will keep its rejuvenation of the EFL Trophy on track by inviting other sides to fill the void left by those who reject the offer.
Leyton Orient president Francesco Becchetti will not be extradited to Albania on fraud, forgery and money laundering charges, a court has ruled.
A number of Premier League clubs have decided to opt out of entering their academy sides into the revamped English Football League Trophy.