The player was technically on loan to Rosslyn Park and therefore not "Effectively Registered" with London Scottish. The club remains in 9th place in the table, now with 17 points.
Chief Executive Tony Copsey: "We are extremely disappointed but, of course, we accept the appeal verdict. The facts of the case were never in doubt; however, we appealed on the grounds that the handful of comparable breaches at Premiership and Championship level in the past three seasons had incurred mainly one - and occasionally two - point deductions; we felt three points was excessive punishment."
MacKenzie had been recalled to provide front-row cover at Plymouth and came on to the pitch in the 47th minute. Scottish lost the game 24-20. However, MacKenzie had been loaned to Rosslyn Park the week before and was still registered to them.
Not completing the paperwork required to re-register him back at Scottish was an administrative oversight from which the club gained no benefit and it happened as a result of a key person in the club's registrations process being on holiday.
The Championship Organising Committee which made the original decision had fully accepted the club's version of events and fully recognised that the club had not sought or received any advantage