Alli was one of the casualties of the Jose Mourinho era at Tottenham as he was cast aside and it almost led to him leaving the club in the winter transfer window.
Following Mourinho’s departure last month, there is an expectation that the midfielder’s career could be resurrected at Tottenham and he made an impact when he started in their 4-0 win over Sheffield United last weekend.
Mason stressed that Alli has trained his way into the starting eleven and he does not concern himself with what happened in the past with him.
The interim Spurs boss insisted that the 25-year-old midfielder is focused on the here and now and has shown the willingness to put in the graft as he is enjoying working in the new environment.
Mason said in a press conference: “I can only take Dele and the rest of the players from what I’ve seen in the last two weeks and I said last week that Dele trained himself into the team last weekend and he did do that.
“Whatever has happened in the past has to remain in the past with Dele.
“As footballers, as people involved in football, and I think in life as well, you have to live in the moment and live in the here and now.
“Dele along with the rest of the group have shown me that they want to work, they want to compete and it has been a good environment to work in, so Dele has been excellent.”
Tottenham are likely to expect their new manager to get the best out of Alli next season.
