Former Blackpool midfielder Angel Martinez is keeping his options open with a number of clubs chasing his signature.
Eintracht Frankfurt have secured the services of forward Haris Seferovic following negotiations with Real Sociedad.
Bolton have sacked Owen Coyle after the club's poor start to the season.
The Trotters, relegated from the Barclays Premier League last term, currently lie 18th in the npower Championship after claiming only three wins in their first 10 matches.
Chairman Phil Gartside said in a statement on the club's official website: "Owen poured his heart and soul into the job, both on and off the pitch, and he led our club with great dignity during some very challenging times."Gartside added: "It is the right time for a change. We set a target at the beginning of the season and want to get back on track.
"I would like to place on record our sincere thanks to Owen, Sandy Stewart and Steve Davis for all their hard work during their time at Bolton Wanderers."
Coyle left Burnley in January 2010 to take up the hotseat at the Reebok Stadium on a two-and-a-half-year deal after Gary Megson was relieved of his duties.
He led the club to safety from 18th position, but failed to keep his side in the top flight last campaign.
Coyle, who played for Bolton between 1993-95, said: "I have always been driven to act in the best interests of the club and care passionately about it.
"I had fantastic times here as a player and it has been a privilege to have held the post of manager.
"I want to thank the fans for their backing since I returned, the chairman Phil Gartside and the owner Eddie Davies for their support and friendship and the club's staff and players for all their effort and commitment.
"I wish everyone connected with Bolton Wanderers all the very best."
Academy manager Jimmy Phillips and head of academy coaching and development Sammy Lee will take temporary charge of the first-team squad, with their first assignment on Saturday at home against Bristol City.
Owen Coyle factfile:
1966: July 14 - Born in Paisley, Scotland.
1985: Begins his professional career with Dumbarton.
1988: Joins Clydebank.
1990: Moves to Airdrie for £175,000.
Finishes season as top scorer in the Scottish League for the 1989-90 season.
Wins promotion with Airdrie and reaches the Scottish Cup final, losing to Rangers.
1992: Appears in the European Cup Winners' Cup for Airdrie as Rangers were competing in the European Cup.
1993: Signs for Bolton for £250,000.
1994: Wins one and only cap for the Republic of Ireland, coming on seven minutes from time in a friendly against Holland.
1995: Wins promotion to the Premiership with the Trotters.
Transferred to Dundee United for £400,000.
Scores winning goal in extra-time in the play-off final against Partick Thistle to help United to promotion.
1997: Joins Motherwell.
1999: Signs for Dunfermline.
2001: Returns to former club Airdrie after a loan spell with Ross County.
2002: Airdrie go into liquidation with Coyle joining Falkirk.
2003: Becomes co-player-manager at Falkirk alongside John Hughes.
Returns to Dundee United as player-coach.
2004: Joins the newly-reformed Airdrie as player-coach following a loan spell.
2005: Takes over at Scottish First Division side St Johnstone and goes on to guide Saints to the League Cup and Scottish Cup semi-finals, while narrowly missing out on promotion to the Scottish Premier League in 2006-07 season.
2007: July - Signs one-year contract extension.
November 22 - Signs three-year contract to become manager of Burnley.
2008: Leads Burnley to League Cup wins over Chelsea and Arsenal.
2009: May 25 - Takes Clarets into the Premier League with victory over Sheffield United in the Championship play-off final at Wembley.
June: Signs contract extension at Turf Moor amid speculation linking him with Celtic vacancy.
2010: January 4 - Burnley confirm Coyle has held talks with Bolton over the managerial vacancy at the Reebok Stadium.
January 5 - The Clarets issue a statement saying Coyle has "reaffirmed his desire to leave Burnley" and join Bolton. The clubs begin talks over compensation.
January 6 - Burnley chairman Barry Kilby voices his disappointment with events and his surprise at Coyle's "sideways" move.
January 8 - Bolton confirm Coyle as their new manager.
May - Keeps Wanderers in the Premier League, finishing 14th, as Burnley go down.
2011: April - Bolton lose 5-0 to Stoke in their FA Cup semi-final at Wembley
May - Bolton finish 14th in the table again.
2012: March 7 - Bolton midfielder Fabrice Muamba suffers a cardiac arrest on the pitch during at FA Cup match at Tottenham. He spends 30 days in hospital.
May - Bolton are relegated by one point after drawing 2-2 with Stoke on the final day of the season.
October 9 - Sacked by Bolton with the club 18th in the npower Championship.