The ex-Arsenal man would be amazed if the Spurs midfielder did not win it.
It has been quite an eight months for the 19-year-old, whose first full season at White Hart Lane has resulted in seven Premier League goals and six assists, helping Spurs mount a serious title challenge.
With the Lilywhites second in the table, five points behind Leicester City, Nicholas feels that Alli is the outstanding candidate, over the likes of Everton duo Romelu Lukaku and John Stones.
"Dele Alli by a mile. I've never agreed with the age bracket, with 23-year-old players able to win it. I'd say they should have to have been 21 at the start of the season," he told Sky Sports.
"Regardless of that it's Alli by a mile. I'd be amazed if anybody else won it. Lukaku will be in the frame if you're talking 23 maximum and John Stones for the first six months of his season.
"However, Everton's league position plays a part, with Spurs in the title race and Alli also doing the business in Europe and for England."
Alli is a shoe-in to be nominated at the very least, with his all-action midfield displays winning matches and admirers for much of the season.
He was signed for just £5 million from MK Dons a little over a year ago, and spent the remainder of the 2014-15 campaign at Stadium MK.
Alli has also helped Spurs reach the last 16 of the Europa League, though he will play no part in Thursday's first-leg trip to Borussia Dortmund after picking up a suspension in the last round versus Fiorentina.
Will Alli win it?