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.
A football agent from Belgium is challenging UEFA's financial fair play rules at the European Commission on the basis that it will lead to a drop in agents' income.
Daniel Striani is being represented by Jean-Louis Dupont, the lawyer who in 1995 secured the Bosman ruling that allowed players to move on a free transfer at the end of their contract.
Dupont believes the 'break-even rule', which prohibits clubs in European competition spending more than their income, "infringes EU fundamental freedoms" such as free movement of capital, of workers (players) and of services (agents).
"Consequently, such restriction of competition and violation of EU fundamental freedoms cannot be justified by the objectives put forward by UEFA," said a statement from Dupont.
He is claiming that overspending should be allowed so long as it is fully guaranteed, such as by bank guarantees.
"In short, the current prohibition... is in practice illegal because the rule is not proportionate, since it can be replaced by another measure, equally efficient but less damaging as far as EU freedoms are concerned," says the statement.
UEFA believes it has already tested the break-even rule's legality with the EU.
"UEFA believes that financial fair play is fully in line with EU law and is confident that the European Commission will reject this complaint," it said in a statement.
"The rules encourage clubs to 'live within their own means,' which is a sound economic principle aiming to guarantee the long-term sustainability and viability of European football."