Only if those 3 hours are classed as "training".
No you need 20 hours of Flight Training with a FAA Authorized Instructor of which 3 hours training is required within 2 calendar months too approve the signoff for the PTS.
Go check FAR 61.109(4), where it states:
3 hours of flight training with an authorized instructor in a single-engine airplane in preparation for the practical test, which must have been performed within the preceding 2 calendar months from the month of the test
If the TSA has not been approved at that time the Instructor and his/her Shool may suffer the wrath of the TSA - maybe not initially but within a year when the TSA stop by to do their audit.
Also there is the long standing debate over the rule of requiring 20 hours of training from an FAA Authorized Instructor.
Now an FAA Authorized Instructor is clearly defined in FAR 61.1(2) which states "a person who holds a current Flight Instructor certificate issued under Part 61" etc.
I know that this has been raised in the past regarding what a foreign ICAO instructor can and cannot do as defined in 61.41.
I do not know if this particular question has ever been challenged with FAA Legal Counsel as to clarifying the definition in 61.1 versus 61.41 and what is stated in 61.109 in regards to the mandatory 20 hours with an FAA Authorized Instructor.
That's a topic for another day.