Both teams are currently fighting for the Champions League, and either of them cannot afford to lose this match. So they are motivated.
Chelsea FC were winless in their last 3 league games, but it is understandable that their oppositions were too strong.
On the other hand, Manchester United failed to grab a win in 3 league games in a row, without any goal scored.
Although Chelsea FC suffered a crashing 0-4 defeat at home in the 1st leg, they earn the bookies’ favor as the AH line is -0.5 for them.
So the favorites are expected to win.