The 21-year-old withdrew from Gary Speed's squad to face England last Saturday after pulling up in training and he was sent for a scan on the injury on Mopday.
Results revealed the winger had suffered a grade one strain - the recovery time for which usually stands from between seven and 10 days.
Spurs will continue to monitor Bale's condition ahead of this weekend's match against Wigan, but his participation in the first leg of the Champions League quarter-final with Real next Tuesday could be in doubt if he does not respond well to the conditioning of the injury.
A statement on the club's website read: "Gareth has returned to Spurs Lodge and took part in controlled straight-line running so we could assess him. We sent him for an ultrasound scan examination this afternoon and that has confirmed the presence of a minor grade one hamstring strain.
"Gareth has reported no pain or stiffness after taking part in the running this morning and we shall continue to monitor him and see how he responds to his conditioning programme throughout the week."
Source: PA
Source: PA