Sunderland are quietly confident Connor Wickham will agree a contract at the Stadium of Light this month after Gus Poyet presented him with a “sign or be sold” ultimatum.

The England Under-21 striker – an £8m buy from Ipswich in 2011 – has one year remaining on his contract and has been stalling on a new deal. Sunderland, though, are desperate to avoid losing for nothing a player currently interesting Leicester and Southampton.

“For me, Connor’s situation is clear,” Poyet said. “He needs to sign a new contract or we let him go – there is nothing in between.”

Sunderland’s manager has become increasingly anxious about a shortage of signings and is demanding that Lee Congerton, the club’s sporting director, secures four more additions before the start of the season.

Santiago Vergini, who can play at centre-half or right-back, is close to completing a transfer from Estudiantes while Poyet remains optimistic that Fabio Borini will accept the £14m transfer agreed with Liverpool and will move to the Stadium of Light.