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, www.bwfc.co.uk.
"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."
Meanwhile Manchester United keeper Tim Howard will join Everton on a 12-month loan deal this summer. The 26-year-old, recently named in the United States' World Cup squad, has been squeezed out of the first-team picture at Old Trafford this season following the arrival of Edwin van der Sar.
Howard was limited to just six senior appearances, with his only Premiership outing coming against Portsmouth in February. After arriving from Major League Soccer outfit New York Metrostars in 2003, Howard initially appeared to be the answer to United's long-standing goalkeeping problems.
However, high-profile blunders in European games at the end of his first season with the club and the start of his second put the US star's place at risk. Despite those problems, and his recent omission, Sir Alex Ferguson remains a big admirer of a player who has played 77 times for the Red Devils.
And, with Van der Sar's contract due to expire in 12 months' time, the United boss has sanctioned a loan move to Goodison Park during which he expects the keeper to prove he is worthy of reclaiming United's number one jersey again.