#2 To prevent falling further behind the chase for Champions League football
The Premier League is widely considered by many to be the most competitive league in the world, as the difference in quality between the top teams is so close that they are almost inseparable and as a result, the competition for top places is always intense.
Manchester United currently lie in 10th place, nine points behind Man City and Liverpool in top place, and the quality of both teams means that Manchester United is almost effectively ruled out of title contention, with their only realistic target being to finish in the top four, thus, cement automatic Champions League qualification.
As it stands, The Red Devils are five points behind Tottenham who occupy the last automatic UCL spot and would be keen to prevent from falling further behind their major rivals.
Anything other than victory against Newcastle could see Manchester United slip further down the table, and worse, potentially go eight points behind both Tottenham and Arsenal. With the way their season is deteriorating, Champions League qualification could be all they could achieve this season, hence would do all in their power to achieve it.