The Welshman is due to travel to London on Friday to complete a season-long loan deal from Real Madrid, the PA news agency understands.
Mourinho played a straight bat to questions about the move on Wednesday and did so again after watching his side survive a scare in the Europa League qualifying second round against Lokomotiv Plovdiv.
Bale's return will tug on the heart strings of Spurs fans after a hugely successful first stint at White Hart Lane.
The Cardiff-born player swapped the north London club for the Spanish capital in 2013 for a then world-record fee, winning four Champions Leagues during a medal-laden stint at the Bernabeu.
But Bale has found himself marginalised under Zinedine Zidane and has spent the last two years struggling to get in the side.
His return to Spurs is also timely for Mourinho after a dismal start to the campaign against Everton on Sunday where they looked void of all creativity in a sluggish 1-0 loss.
They also needed two goals in the final 10 minutes to overcome Bulgarian outfit Plovdiv, having gone a goal down with 19 minutes remaining.