Rooney walked out alongside Kai and youngest son Klay for his 100th England cap in a UEFA Euro 2016 qualifier against Slovenia at Wembley in November.
Kai will do the same again at Old Trafford after Rooney revealed the news via Facebook on Saturday.
The 29-year-old wrote: "Big game tomorrow against Tottenham at Old Trafford. Looking forward to walking out again with my son Kai as mascot!"
Rooney will be hoping the little mascot brings him some luck, with United clinging onto the fourth and final UEFA Champions League spot by just two points.
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