Liverpool are already the champions of the Premier League, with all confidence you can say as much, I don't really think Liverpool performance will drop this season, you can say for next season but not this season. Even a spell may probably not be able to stop Liverpool from winning the Premier League this season, reason is the goal difference, they are 67 points while the closest next to them is Arsenal with 54 points, so you can see the difference. Liverpool are passing Arsenal with 13 points but have played more game than Arsenal, so actually there is no come back from Arsenal or any other club in the Premier League.
Of course, it will be impossible for Arsenal or another premier league club to shift Liverpool's position with the current points. Even if Arsenal will win all remain in the match, and Liverpool of course will not let their position be easy to shift, they will also win the remaining match to secure the position. Tonight they will host Southampton on Anfield, and this club is the team at the bottom of the rankings. They are predicted to win easily with a lot of goals, and become a revival event after they lost on FA cup with underdog team. This is certainly a very interesting match because in a previous competition, Liverpool considered having a dilemma after implementing a "parking bus" on champions league when meet PSG.