Man United was held to a surprise 1-1 draw with relegation candidates West Brom at the Hawthorns Stadium last weekend.
The Red Devils will host Newcastle United at Old Trafford tonight.
Ole Gunnar Solskjaer’s side has only managed to win two of their last six matches in the Premier League and are in the second position on the log with 46 points from 24 games.
“If [Manchester] United continue to keep dropping unnecessary points to weaker teams, I am going to be worried for them making the top four,” Berbatov told Betfair.
“When you’re challenging for the title it’s unacceptable to drop points against the team that’s bottom of the table and then the team second bottom of the table.
“Yes, you may drop points against the likes of City and Liverpool, when there is so much quality on the pitch but playing against teams down the table, you’ve to take the points otherwise you bring lots of problems on yourself.
“United must kick on because they risk teams catching them and each week, the race for a top-four spot is getting tighter.”
