The England captain stayed rooted to the bench at Deepdale after struggling with illness all week, the first time he has missed a game all season after 29 consecutive club starts.
But it mattered little as Son boosted his confidence amid a poor season by his lofty standards with a fantastic second-half brace that broke the resolve of Championship side Preston, who conceded another late on as Danjuma swept home to cap off a lively cameo that showed what he could offer for the remainder of the campaign.
Antonio Conte made seven changes in total from the side that claimed a crucial 1-0 victory over Fulham in the Premier League on Monday night, with Craven Cottage match-winner Kane joined on the bench by Villarreal loanee Danjuma.
Only Rodrigo Bentancur, Heung-min Son, Dejan Kulusevski and Ivan Perisic retained their starting berths in Lancashire, with the latter moved from wing-back into the front three with Kane absent. Richarlison did not make the squad after an injury setback, with Hugo Lloris also given the night off after a rough few weeks.
Preston, meanwhile, showed two changes from their win over Birmingham, with Spurs loanee Troy Parrott ineligible to face his parent club and Manchester City’s Liam Delap cup-tied. Ben Whiteman and Ched Evans came in as Ben Woodburn dropped to the bench.
Debut delight: Arnaut Danjuma capped off a lively cameo by scoring a third goal off the bench
/ REUTERSThe first half was a real war of attrition desperately short on quality, with Spurs dominating possession but unable to break down a disciplined and stubborn Preston rearguard.
The badly out-of-form Son looked livelier as he forced two strong saves from Freddie Woodman with efforts from outside the box, while Kulusevski was also denied by some expert last-ditch blocks.
Organised Preston had no forward threat whatsoever but went in at the interval fully content having done their defensive duty in diligent fashion.
But Spurs started the second half in more purposeful mood, moving the ball around with more pace and precision in search of an opening goal that came on 50 minutes – Son finding himself in a pocket of space and curling an unstoppable effort into the bottom corner.
A low-key game opened up after that stunner, with Preston rallying and Whiteman firing wide before Woodman had to push Perisic’s header over the top.
But the fight was taken out of the Championship side when Son received a pass from Perisic and took a touch before turning Jordan Storey and rifling in a second off the fingertips of Woodman.
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