Alli became a fixture in the Tottenham team after making his debut as a teenager in 2015 and was a regular starter for England.
However, he was in danger of disappearing off the radar this season with niggling injuries, loss of form and speculation swirling that he did not fit into manager Jose Mourinho's plans.
He has made only one Premier League start, on the opening day of the season against Everton, since when he has been limited to cameo appearances mainly in cup competitions.
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But there are signs that Alli, who has scored 50 goals and credited with 33 assists in 162 Premier League appearances for the club, is finally recovering his spark.
As well as his overhead goal against Wolfsberg he also set up a goal for Carlos Vinicius and another for Gareth Bale, who is also beginning to show some of his best form.
Bale is likely to start against Burnley in the Premier League on Sunday and Alli will surely be involved too. However, Mourinho scoffed at suggestions that Bale, Alli, Son Heung-min and Harry Kane might all be unleashed from the start against Burnley.
"Do you give me four names or 11? Four or eleven? Do you want to give the other seven? I do the other seven and you do the four!" Mourinho said on Friday when that was suggested.
"Well, you could see against West Ham (United), was not from the start of the game, but for 20 minutes or so, we had Bale, Lucas (Moura), Dele, Harry, Sonny. So you had it. We didn't turn the result around. We didn't score to win that game, but we could leave the game with positive feelings."
Asked specifically about Alli, Mourinho said he was happy with his improvement.
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"I'm happy with him. Small injuries are mentally not good, players getting disappointed, lack of motivation, frustration. He went through all that," Mourinho said.
"He came back. We had good conversations, training well, playing minutes or part of matches. Not yet a 90 minute match but he went through periods and basically now 75 or 80 minutes."
Tottenham's 4-0 win over Wolfsberg on Wednesday secured their place in the Europa League last 16 where they will face Dinamo Zagreb.
Burnley will be tougher opposition on Sunday, however, as Tottenham emerge from a run of five defeats in six league games which has left them in ninth spot in the standings, nine points off the Champions League places with a game in hand.
"Burnley is Burnley, Sean (Dyche) is Sean and the players are the perfect interpreters of what he wants from the team," Mourinho said of Sunday's opposition and their coach.
"Easy to analyse, difficult to play against. You have to be solid defensively, if not you know they can score."
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