But they face Premier League competition with West Ham also interested in signing the striker.
Seferovic has shared the central starting position at Benfica with Carlos Vinicius this season, although the latter has been far more prolific in front of goal.
Vinicius has found the net 11 times in the league having started just eight games while Seferovic has scored just twice – his last coming in September.
While Tottenham are still hoping to bring in a secondary striker, they have now signed Giovani Lo Celso on a permanent deal.