Despite operating under a transfer embargo, Portsmouth have agreed a loan deal for Stoke City defender Ibrahima Sonko.
Portsmouth are currently in administration and are not permitted to sign players. However, the Football League does relax those rules if a club has less than 20 players on their books.
Portsmouth are now awaiting confirmation from the league that they can sign a player who made nine appearances on loan at Hull City last season.
"He's a big, strong and very powerful defender," Cotterill told the club's official website. "I've followed him for a while and I thought he did a fantastic job at Reading.
"He's been a bit unlucky during his time at Stoke and hasn't had too many first-team opportunities, although he did spend time on loan at Hull last season. He just needs to get back playing football.
"I spoke to him before we flew out here to the USA and hopefully he'll be able to come and join us on tour. The deal is done and we're just waiting for the okay from the Football League."