Bolton have confirmed Matt Jansen, Khalilou Fadiga and Oscar Perez will join Jay Jay Okocha and Bruno N'Gotty in leaving the club this summer.
Manager Sam Allardyce is hoping to thrash out a deal with Ivan Campo, whose contract is due to expire, while it is possible Fiorentina midfielder Hidetoshi Nakata could return to the Reebok after his loan spell ended.
'Although Hide has returned to Fiorentina following the end of his loan spell, we are hopeful of bringing him back on a permanent basis,' said Allardyce.
'However, there is a long way to go, in terms of discussion, before we can conclude a deal.'
The Bolton boss is looking to strengthen his squad this summer after the club's bid for European football disappointingly fizzled out in the last few weeks of the campaign as they finished eighth.
Top of his list is a new striker, although Allardyce will also have to find an able replacement for influential defender N'Gotty.
'We need six quality players to bolster our squad for the coming season and a vigorous recruitment process will begin in earnest,' Allardyce told the club's website.
'My objective is to bring in the majority of these players before the World Cup begins next month.
'I have scoured the globe to bring in the right quality we need. It is a difficult and delicate process but one that I will relish as we aim to continue our progress in the top-flight of English football.'