Whereas Liverpool met Sevilla in the group stage of this season's Champions League and their travelling support were charged £54 each for a match ticket, the visiting Man United supporters are being asked to fork out £89 each.
It came after Liverpool supporters were charged £54 to see their side at the same ground during the group stages in November.
"This has been raised with Sevilla, and internally, but ultimately Sevilla have not agreed to significantly lower the price of tickets for our fans to what we view as a reasonable level".
United have matched the figure that Sevilla have insisted on charging visiting fans for the first leg in Spain, and the Red Devils will use the proceeds from their ticket sales to refund £35 to their own travelling supporters.
United however have made a decision to subsidise their fans making the journey to Spain, by charging Sevilla fans the same price at Old Trafford and giving the extra £35 back to their fans with any left over funds being donated to the Manchester United Foundation.
"Sevilla will also look to guarantee that no Sevillista pays a penny more than any Manchester United fan for similar tickets - as competition regulations dictate".
"As a result of the changes to ticket prices for away fans, should we gain any additional revenue after having refunded our supporters, we will donate this to the Manchester United Foundation".
"Our primary objective was to ensure our fans didn't end up paying this much".
United have reportedly offered 2,995, which is 4.1 per cent of the stadium's capacity when rules state it should be five per cent.
"Right now everything is hypothetical as United have not informed the club officially of the price rise", added the source.
Manchester United have announced they will subsidise ticket costs for supporters travelling to the Champions League clash with Sevilla after the Spanish side refused to lower their prices.
Sevilla were accused of setting "exorbitant" prices when it emerged they would be charging United fans at least £89 for the game. "We are delighted United have fought our corner on this issue".