MANCHESTER: With Manchester United on its longest winning run in eight years, it's tempting to conclude that a giant of English soccer is starting to resemble the force of old.

Some perspective is needed, however, when assessing United's nine straight victories in all competitions since Dec. 8.

Only one of its opponents in that one-month period could be classed as a major rival: Tottenham. And that 1-0 win came on December 11, when Spurs weren't showing the kind of form they are at present.

Otherwise, United has proved to be ruthless in sweeping aside teams who most likely won't finish higher than mid-table in the Premier League or were plucky underdogs in cup competitions, like Reading in the FA Cup or Zorya Luhansk in the Europa League.

Bigger tests lie in wait for United and they start with the visit of Liverpool in the league on Sunday.

What is traditionally the biggest game on the English soccer calendar is a chance for United's players to prove they really are a force to be reckoned with this year and that, maybe, they could still be title contenders.

Win at Old Trafford and United would close to within two points of Liverpool, which heads into the 21st round of games in second place. First-place Chelsea has a 10-point cushion over United with half the season gone, and plays champion Leicester away on Saturday.

It will be interesting to see how United manager Jose Mourinho approaches the game against Liverpool. He deployed defensive tactics to grind out a 0-0 draw at Anfield on Oct. 17, bringing the free-scoring Liverpool juggernaut to a halt. And he couldn't hide his satisfaction at neutralizing a team he sarcastically labeled as "the last wonder of the world."

Three months on, United will be expected to be more attacking at Old Trafford, especially since that's the way the team has played during its winning run, when goals have come much easier. Should striker Zlatan Ibrahimovic shrug off an illness to play, the 35-year-old Swedish striker will be looking to add to a record of 12 goals in his last 12 games.

There's no doubt that Mourinho has United purring, with its attacking play quicker and sharper now that Paul Pogba and Henrikh Mkhitaryan are fixtures in the team and in more advanced roles. Suddenly, there is a heightened sense of expectation during games at Old Trafford.

It might also be a good time to play Liverpool, even if the Reds have won four of their last six league games — including against Manchester City and Everton — and drawn the other two to become Chelsea's closest challenger.

Sadio Mane, one of Liverpool's brightest attacking sparks this season, has just left for the African Cup of Nations, while Philippe Coutinho, another member of the lively forward line, has only recently returned from injury. There are doubts over whether two key members of Liverpool's defensive set-up — holding midfielder Jordan Henderson and center back Joel Matip — will start after injuries, too.

A day after United beat Hull 2-0 in a League Cup semifinal first leg to move to its longest run of wins since January-February 2009, Liverpool was fortunate to escape with only a 1-0 loss at Southampton in the other semifinal first leg.

Momentum, suddenly, has swung United's way ahead of the latest battle with its northwest neighbour.