United have moved to swell their ranks with new faces over the last three years and currently employ 58 scouts across the world, says the Daily Mail.
The major restructuring has been championed at Old Trafford but is causing serious concern for Mourinho, who wants a more streamlined operation.
A change in the scouting set-up was required after the retirement of Sir Alex Ferguson in 2013. Ferguson trusted a small circle of scouts and contacts to make signings but there was a realisation that United needed to modernise.
The number of scouts at the club is acting as a source of growing frustration for Mourinho, however. The Portuguese is believed to be perplexed at the scale of the department and privately argues the operation can be far more efficient.