The Mourinho era began in promising fashion for the club and Alli was a key beneficiary of the Portuguese's arrival.
An upturn in form in light of Mauricio Pochettino's departure was short-lived, though, while Bale's sensational return to north London has been the epitome of a damp squib.
Both players were once regarded as two of world football's biggest superstars but now represent mere backup options in a Spurs side that has faltered in recent months.
And in light of the Lilywhites' alarming dip, which has left them struggling for a place in next season's Champions League just months after threatening to challenge for the Premier League title, Sky Sports pundit Gary Neville has suggested that Mourinho needs to find a way to deal with the issues surrounding Alli and Bale.
While speaking on Monday Night Football, Neville had some strong words to say about the aforementioned duo.
"He has got to bring Dele Alli and Bale round and I am not saying that he has to pander to these players because Gareth Bale has wound me up all season just watching him smile on the bench.
"Dele Alli, I worked with him for England, I think he is a brilliant talent but he should be doing a lot more. I want more from him. He is an outstanding player. Deliver on a great career. There is a reason why his career is going like this and it is not just Jose Mourinho, Dele has got to get over that himself.
"So for me, the Dele Alli and Bale situations need getting hold of and dealing with properly. That might mean that Jose Mourinho has not got the same control over top players that he had a few years ago when he was winning league after league and could do as he wanted or he will have to change how he deals with players."
GIVEMESPORT's Jack Saville says...
That Alli and Bale are both on the periphery of Spurs' first-team squad right now speaks volumes about the state the club are in.
Concerns over their inability to establish themselves in the first-team have rumbled throughout the season, and the steadily increasing problems under Mourinho have brought their respective situations into sharp focus.
As Neville alludes to, there are mentality issues for both Bale and Alli to deal with which are holding them back.
Alli's form stagnated dramatically long before Mourinho took the reins at Spurs, while Bale's fractured relationship with Zinedine Zidane at Real Madrid, which was played out in front of the world media, is beginning to look like more than a miscarriage of justice in the midst of a power struggle between club and player.
With the Wales international set to return to Los Blancos at the end of the season, there are bigger issues for Mourinho to deal with and Alli is one of them.
Mourinho's decision to hand Alli 26 minutes worth of action against Manchester City last time out, which was his second-longest league run out of the season, hints that the England international may get another chance to prove himself in the coming weeks.
Given how dramatically Alli has declined this season, he may well be playing for his future in north London during the final months of the season.News Now - Sport News