Lack of Proper Replacements
While there is no dearth of midfield talents at the Lane, with plenty of options in the likes of Moussa Dembele, Moussa Sissoko, Victor Wanyama and Harry Winks, but none of them, with the exception of Sissoko, can play in the advanced role that Alli has excelled in.
The goals that Alli brings to the team from the middle of the park, along with his quick thinking and electric feet make him absolutely invaluable for Pochettino and Tottenham. His presence in the final third catalyses the entire team and his flair and the penchant eye to pop up in right positions at the right time is unrivalled.
Selling Alli would create a huge void in the attacking half of the pitch for Spurs and they would struggle a big time to replace his talent in a short time and hence should keep hold of the 20-year old.