Phillips experienced defeat for the first time this season during Tuesday night's 2-0 loss at home to Preston North End in the Carabao Cup with the 22-year-old part of a much-changed Whites side that featured nine alterations to the team that recorded last Saturday's 3-0 league win at Norwich City.
Yet Phillips admits the Championship is very much United's priority with the midfielder keen to forget Tuesday's mishap against Preston and in buoyant mood ahead of tonight's showdown with second-placed Boro at Elland Road.
"Obviously we were gutted about the game on Tuesday night but I think we can put that aside now," said Phillips.
"It's been and gone.
"The main focus is the league and Friday is a massive game at a full house Elland Road and we are just looking forward to showcasing what we have been working on.
"I thought personally we weren't ready for the game against Preston but we have to change that and Friday is a massive game and we are just looking forward to getting out there and proving us right."
Just goal difference separates Leeds and Boro at the top of the Championship and victory for either side would send them three points clear heading into the international break.
Phillips admits United will need to be wary of Middlesbrough's aerial threat but the midfielder says United will be first and foremost focused on their own exciting style of football implemented by Bielsa.
"They will be very physical," admitted Phillips.
"They have got a lot of big players and we are expecting obviously an aerial game which we have been working on and we are just looking to work on our play and not really bother about them. I think if we do that right then we will get a good result.
"We are just looking forward to getting out there and putting the disappointment of Tuesday night behind us and getting a victory."