Allen was forced off during the first-half of Wales’ 1-0 defeat at the hands of the Republic Of Ireland, a result that has rules the Welsh out of the 2018 World Cup in Russia.
The former Liverpool playmaker appeared to suffer a head injury at the Cardiff City Stadium and now the 27-year-old faces a race against time to be fit for Saturday’s trip to the Etihad Stadium, amid claims he suffered concussion.
Allen has been a key figure for manager Mark Hughes this season and the loss of the Welshman would be a blow to Stoke ahead of a trip to the Premier League frontrunners.
Manchester United could try and lure Chelsea's Willian to the club as part of a deal that will see Anthony Martial move the other way.
Lionel Messi says Argentina have not let their heads drop despite only managing a 1-1 draw against Iceland on Saturday.
Crystal Palace are showing an interest in Chelsea striker Tammy Abraham and are keen to take him on a season-long loan deal.
Tottenham are being linked with a £30million swoop for Inter Milan midfielder Matias Vecino, but will face strong competition.
Manchester United are out of the running to sign Cristiano Ronaldo because they want Gareth Bale instead, reports have claimed.