The 19-year-old has emerged as one of Europe's hottest properties following a rip-roaring first season at White Hart Lane, which has resulted in seven goals, 12 assists and repeated call-ups by England boss Roy Hodgson.
His stock rose even further last week with a brilliant midfield display in the Three Lions' 3-2 victory away to reigning world champions Germany in Berlin.
In January, ex-Liverpool boss Brendan Rodgers revealed that he was close to striking a deal with Alli's former club MK Dons for the starlet (Sky Sports), but the deal never happened, with the Daily Mail reporting that the Reds' hierarchy passed on him.
Suffice to say Alli's emergence has since left a bitter taste in Aldridge's mouth, with the Republic of Ireland legend conceding that the missed opportunity sickens him.
"Dele Alli is going to be a star - make no mistake about that. I baulk at the fact that Liverpool had this kid and let him go. We’ve bought so many inept players over the last few years for so much money and you look at what we turned away, it really hurts me to see," he wrote in the Liverpool Echo.
"The kid wanted to play for Liverpool, he was a fan who loved Steven Gerrard when he was younger. He had a manager at MK Dons in Karl Robinson who was keen for him to go to Liverpool.
"So to miss out on him and to now see what he’s doing for Spurs and for England, it is hard to take."
Alli is expected to face Liverpool at Anfield this Saturday as the Lilywhites visit Merseyside hoping to keep pace with Premier League leaders Leicester City, who sit five points ahead of them.