Manchester United manager Louis van Gaal has refused to rule out the possibility of signing goalkeeper Victor Valdes.
Manchester City boss Manuel Pellegrini says he is confident that England goalkeeper Joe Hart will sign a new contract.
Roberto Di Matteo has been installed as the odds-on favourite by Sky Bet to succeed Paolo Di Canio as manager of Sunderland.
The Black Cats are bottom of the Premier League table as the only side without a win this term and Di Canio has paid the price for that poor start with Sky Bet offering 11/10 on them to be relegated.
Di Canio only took over at the Stadium of Light in March and successfully kept the club in the top-flight as Martin O'Neill's successor last season.
Ex-Brighton manager Gus Poyet and former Aston Villa chief Alex McLeish are two of the other early contenders.
Sky Bet's Football Trader Chris Spicer said: "We made Di Canio 1/2 to be the next Premier League boss to go following their 3-0 defeat to West Brom on Saturday.
"However, late on Sunday evening we took a sizeable bet from a Sunderland-based punter and it wasn't long before the money started to flow. We went as short as 1/12 before the news was confirmed.
"We entered Di Matteo as the favourite to succeed him at 5/2, but it was swiftly picked up by the punters and we're now firmly odds-on that he'll be their next boss."