England goalkeeper Fraser Forster does not know if he will still be at Celtic when they next play in Europe.
Norwich captain Sebastien Bassong has signed a new two-and-a-half-year contract.
Rangers have confirmed to the London Stock Exchange that chief executive Charles Green has offered to resign from his position with immediate effect.
Green is expected to leave the company by the end of May, with the search for his replacement already under way.
The Yorkshireman took the decision to step down following "negative publicity" in recent weeks over his consortium's acquisition of the club last summer, but, "strenuously denies any wrongdoing".
The Rangers board announced last week plans to commission an independent investigation following claims by former owner Craig Whyte that he was involved in Green's takeover.
Whyte has alleged close links with Green and commercial director Imran Ahmad when their consortium completed the purchase of Rangers' business and assets last summer.
Green - who recently apologised after being charged by the Scottish Football Association for allegedly using "racist and offensive language" - refuted the allegations by Whyte, who was in charge when the club plunged into administration and subsequently liquidation.
Green said in a statement on Friday: "Recent events have undoubtedly been a distraction for both myself and all involved with Rangers and I feel that it is appropriate that I step down so that The Club can continue to progress back to where it belongs at the pinnacle of Scottish football."
I am very proud to have been associated with a club of the stature of Rangers and am proud of the achievements of The Club during my tenure as Chief Executive.
"My thanks go to the Rangers fans, whose support has been tremendous during my time at The Club."
A statement to the Stock Exchange confirmed: "The Company announces that Charles Green has notified the Board that he wishes to step down as Chief Executive with immediate effect.
"Recent weeks have seen media interest in the circumstances surrounding the period prior to the acquisition of The Club by the consortium led by Mr Green.
"Whilst Mr Green strenuously denies any wrongdoing, he has recognised that this negative publicity is a distraction and is detracting from the achievements and reputation of The Club.
"As a result, Mr Green has informed the Board that he will leave his post with immediate effect and leave the Company, following an orderly handover, by the end of May.
"The Board has commenced the search for a new Chief Executive and expects the role to attract high quality candidates from both within and outwith the industry."A further announcement will be made in due course."
Rangers raised more than £22million through a share issue in December and chairman Malcolm Murray paid tribute to Green for his efforts during his time as Ibrox chief.
He said: "Charles Green was instrumental in helping to secure financial stability for The Club.
"The impact that he had in turning The Club around from the dark days of last summer will never be forgotten by the fans who I am sure, like me, will thank him for this and for choosing to put The Club ahead of his personal position at this time."