The Tottenham Hotspur team-mates square off at Euro 2016 today.
The 20-year-old midfielder scooped PFA Young Player of the Year last season following a magical first year at Tottenham, scoring 10 Premier League goals and setting up 12 in all competitions.
For all his talent, though, there is an ugly streak to the hugely-talented England international, who faces Welshman Davies in a massive Group B clash at Euro 2016 this afternoon.
In April, Alli was given a three-match ban for punching West Brom's Claudio Yacob, with that incident coming a month or so after he kicked out at a Fiorentina player during a Europa League contest in Florence.
Dele Alli celebrates after scoring the first goal for Tottenham
"With what he has done this season, people are going to be looking at him now, not just for the quality of his football but he will be scrutinised for his behaviour as well," Davies said via Reuters.
"You can have a laugh about it after it has happened but he's probably been fortunate that it hasn't affected his game but he's also won us games as well."
He is hugely gifted, but if there is something that will hold him back during his career it'll be his personality, but it very much contributes to the player he is.
But there is the sense that it is a matter of time before it lands him in even bigger trouble on the pitch.
England's Dele Alli