Former United captain Keane has claimed that there is "a long way" back for the English giants if they want to be regarded as title challengers once again.
"I don't know where to start. I knew they weren't in a great place, but I'm shocked and saddened at how bad they were today," Keane told Sky Sports News. "Lacklustre, no quality, lack of desire, lack of leaders. There's a long way back for United, it's scary how far they've fallen."
Marcus Rashford picked up a groin problem during the clash on Sunday afternoon, and Solskjaer admitted after the match that the England international is facing an extended period on the sidelines.