New boss David Moyes has come under criticism after United made a slow start to the season, but three wins on the bounce scoring nine goals on the way has turned a few heads.
The champions are now eight points adrift of leaders Arsenal but they are expected to spend big in January after missing out on a number of targets in the summer.
Striker Robin van Persie is also on the mend and Berg expects Moyes’ team to continue to rise up the league and eventually put in a challenge at the summit.
“Manchester United are on the way up,” Berg said.
“I expect them to kick on, continue this form and really impose themselves. They’ll get the points they need.
“They’ll put in a really good challenge for the top, hopefully they’ll be top four and maybe they can challenge for the championship, it’s not that many points off.
“You know what happens after Christmas, there are going to be teams that struggle and some that go on good runs.”