Townsend spent the final two months of last season on loan at The Den, scoring twice in 11 appearances, and the 20-year-old has expressed an interest in spending another loan spell with the South London side.
"If Tottenham decided to send me back to Millwall I would be delighted," Townsend told the South London Press.
"I owe [Millwall manager] Kenny Jackett a lot because he signed me last season when nobody else wanted me. He put a lot of faith in me and did a lot of good for my career."
Townsend has played just once for Tottenham's first team, opening the scoring in a 3-0 victory over Charlton Athletic in last season's FA Cup.
The young winger has also previously served loan spells at Yeovil Town, Leyton Orient, MK Dons, Ipswich Town and Watford.
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