Spurs will be looking for defensive reinforcements this summer, and one youngster may be brought back to the club just a year after leaving.
Long thought of as one of the most promising young English centre backs around, it appeared an £8 million fee was surprisingly enough for chairman Daniel Levy, and with that, Caulker was off to newly promoted Cardiff.
Caulker has been one of the few bright spots for the Welsh outfit this year, with the Bluebirds relegated and looking odds on to finish bottom of the division.
Seizing the captaincy at the club didn't help Cardiff stay up, but would have almost certainly helped Caulker's mental game, and there is still a strong chance that he may go to Brazil as part of England's World Cup squad.
Still just 22, Caulker must surely be an attractive option for a Spurs side that have leaked goals this season.
With uncertain futures over many of their own centre backs, bringing in someone who knows the club would be sensible business - especially if a buy-back clause or first refusal exists as part of Caulker's transfer to South Wales.
Caulker himself indicated a willingness to stay and help Cardiff up again next year, telling BBC Sport: "I signed a four-year deal here so I'll be looking to get us back promoted next season."
The Guardian reported interest from Spurs last month, and if his childhood club come calling, and if England recognition depends on what division he'll be playing in next year, that willingness may waver.