Hughes saw his team defeated 2-0 at United yesterday.
And the Red Devils legend insisted afterwards: "They could win everything.
"They are ticking games off and when you get to this stage of the season, they have been here, understand what needs to happen and what it takes.
"It is a big ask. Sir Alex would say himself it is very difficult to do.
"But trust me, it is something they will try and achieve. Good luck to them."