Luton have made their ninth summer signing following the arrival of winger Danny Green.
Notts County have signed Togo international Mawouna Amevor on a two-year deal.
Napoli claim Manchester City have pulled out of the race to sign Edinson Cavani because of his asking price.
President Aurelio de Laurentiis, speaking at a news conference to officially unveil Rafael Benitez as the Serie A club's new manager, told reporters City were not prepared to meet a £54m buy-out clause for the striker.
"Manchester City do not have money to pay for Cavani becasue they say we won't pay that," De Laurentiis said on Friday.
"Abu Dhabi (City's owners) say they would never pay 63m euros for Cavani."
Chelsea, PSG and Real Madrid are all in the hunt for the 26-year-old Uruguay international but De Laurentiis believes his departure is far from inevitable.
"With Edinson nothing has changed," he added. "Headlines I've read in the papers did not represent his words exactly.
"He could never deny the importance of a club like Real Madrid's, but don't forget that he made his name at Napoli.
"If a club like Anzhi (Makhachkala) enquire about him, maybe he says no, but other clubs like Bayern (Munich), Barcelona or Real Madrid could persuade him to leave.
"He knows that he has a contract and an obligation to us, and there is a buy-out clause.
"Cavani knows that at Napoli he is the most important player. I do not know whether, at Real Madrid or in other teams, he will be as important."