Newcastle are being found out this season, claims Manchester United manager Sir Alex Ferguson

Sir Alex Ferguson's players were put to the sword by Newcastle United at the turn of this year in a fashion which suggested, in a very real way, that there would be no permanence about their grip on British football. It was not so much the 3-0 New Year scoreline on Tyneside as the desperate manner of defeat, five days after humiliation by Blackburn Rovers on Ferguson's 70th birthday.

A year being such a long time in football and Ferguson being Ferguson, the two sides stand 23 points apart ahead of their clash tomorrow at Old Trafford, a stadium where Newcastle have not won since their 2-0 victory in February 1972. The United manager reflected ahead of the game that Alan Pardew's side simply are not the surprise package they were when Yohan Cabaye and Demba Ba burst onto the Premier League scene last season.

"The new players they brought in caught us all by surprise," Ferguson said. "We didn't really know a lot about them. I knew about Ba, of course, but I didn't know anything about Cabaye or [Papiss] Cissé to be honest with you. They had fantastic seasons. Second time round, clubs are starting to analyse them a bit differently."

Injuries are also a factor, with Cabaye and Cheikh Tioté out until next year. "He's had one or two important players injured and that does make a difference when you've not got a squad as strong as the likes of ourselves or City or Chelsea," Ferguson said of Pardew, whose 14th placed side are only five points off the relegation places. "I'm not entirely surprised, although I am surprised they are so low down the table."

The draw at Swansea on Sunday reduced United's lead at the top of the table to four points from the previous weekend but in Wayne Rooney they have a player needing to make up for arguably his worst game of the season, in South Wales.

"Yes, to be honest [it wasn't one of my best days] and I could feel it on the pitch," the England forward said. "Some days you have an off day I could feel that out there on the pitch and you know I have no problems with getting substituted because it was not one of my best games."

It was an honest assessment from a player whose Boxing Day night out with Tom Cleverley and Jonny Evans last year ended with him arriving at Carrington in state which left him unfit to train, in the opinion of his manager – who subsequently hit him with a £200,000 fine and dropped him. "Of course, the thing about football and especially over the Christmas period is that you have a game every few days," Rooney said. "The [Swansea] game has gone for me and it is certainly not one I will remember. I will just move on to the next one."

Rooney did not share his manager's fury with Swansea defender Ashley Williams, whom Ferguson implied had deliberately cleared a ball into the back of Robin van Persie's head during the second half at the Liberty Stadium. "It was one of those things," Rooney said. "The whistle had gone and the defender has gone to clear it and it has hit him in the head, so I think probably the right decision from the referee."

With a home game against West Bromwich Albion on Saturday before the New Year's Day visit to Wigan Athletic, United will believe they can re-establish a six-point lead over City. "This is a great opportunity to try and make that gap even bigger. Unfortunately [at Swansea] we couldn't do that but we have two home games and hopefully we can get six points out of them," Rooney said.