The Sky Sports pundit believes that Aston Villa will continue to be a bogey team for Arsenal, especially considering their fantastic start to this season.
Currently sitting second in the Premier League, the unbeaten Villa will hold Arsenal to a 1-1 draw Villa Park tomorrow according to Merson, who played for both clubs during his 21-year professional career.
He said in his weekly prediction: "To be fair, his team (Paul Lambert) are doing well and are well organised with Gabriel Agbonlahor working hard up front.
"They always cause Arsenal problems, as we saw last season and even though Arsene Wenger needs a win I think we will see a draw."
The Gunners were thumped 3-1 by Paul Lambert's side at the Emirates last season, but narrowly beat them 2-1 in the return match later in the campaign.
Arsenal fans certainly won't be happy with anything less than a victory tomorrow, especially considering their dismal showing in the midweek Champions League lose to Dortmund.
The Foxes have had a impressive start to life back in the top-flight, mainly down to the goalscoring form of new striker Leo Ulloa. They currently lie in 12th position with 5 points, which is level with Louis Van Gaal's side.
Merse predicts United will come out victorious, but believes the game will be very entertaining for the neutral:
"I've been impressed with Leicester all season long...
"However, I don't see them taking anything from this one because Man United are starting to get on a roll.
"They are the team to watch this year because they'll concede goals and score goals - and Leicester are the same. This should be an entertaining game."
As for the rest of the league Merson believes Costa will be pivotal in the Manchester City/Chelsea clash; he predicts a 1-1 draw if he plays and a 2-0 City win if he doesn't.
The following are the rest of the 46-year-old's predictions in full: Aston Villa 1-1 Arsenal, Burnley 1-1 Sunderland, Newcastle 2-2 Hull, Swansea 2-1 Southampton, QPR 1-1 Stoke, West Ham 1-2 Liverpool, Leicester 2-3 Manchester United, Everton 3-1 Crystal Palace, Man City 1-1 (with Costa) 2-0 (without) Chelsea.