Doncaster have made forward Dany N'Guessan their sixth summer signing.
Tottenham have confirmed that Romanian defender Vlad Chiriches has completed a move to Napoli.
Norwich midfielder Jacob Butterfield has joined npower Championship side Crystal Palace on an emergency loan deal until February 19.
The 22-year-old joined the Canaries from Barnsley during the summer, having fought his way back to fitness from a long-term knee injury.
Butterfield had an eight-match loan spell at Bolton earlier in the season, but did feature for Norwich in their 3-0 FA Cup third-round win at Peterborough on January 5.