Tottenham's midfield options are being stretched. Expect to see George Marsh promoted.
His absence will create a headache for manager Mauricio Pochettino, who is already without Victor Wanyama and Mousa Dembele due to injury.
It is why Pochettino has pushed on with giving Oliver Skipp chances, with the 18-year-old midfielder starting his first Premier League game in the win over Burnley.
Skipp may now be joined in Tottenham's first team by another under-23 teammate as the club look to plug the gap created by Dier's absence.
Tottenham dropped a hint who is next in line, after letting George Marsh train with the first team in Barcelona last week.
Football London reported Marsh joined Skipp and young striker Troy Parrott in the session.
Marsh didn't make the bench for Spurs at the weekend, but with rotation required over a hectic schedule, he could get his chance.
The 20-year-old has been a regular for the under-23s this season, captaining the side.
He is a defensive midfielder and would play a handy back-up for Dier, especially with Luke Amos having sustained a long-term injury.
Spurs face Arsenal in the League Cup this week, before fixtures away to Everton, and at home to Bournemouth then Wolves to close out the year.
It would not be a surprise to see Marsh involved in one of the matches with Tottenham's squad already stretched, and he could even feature against Arsenal in midweek.
Have something to tell us about this article?