Manchester United and Tottenham Hotspur lead chase for Newcastle United's in-form striker Demba Ba Redknapp has also claimed that the figure is lower. Newcastle sources have suggested that Ba can only leave if a club in the Champions League comes in for him but this has been questioned by some of the clubs who are considering making a move. Ba signed a three-year deal on Tyneside and is believed to earn a basic £35,000 a week plus £20,000 per first-team appearance. The terms of the deal reflect the player's medical history and his well-documented knee problem, which scuppered a move to Stoke City before he joined West Ham. Ba failed his medical at Stoke - with Tony Pulis famously describing the striker's knee as a "ticking time-bomb" - and it is highly likely that he did not undergo a medical at Newcastle which helps explain the complicated nature of his contract. However, despite his fitness concerns he has full mobility and has been available for the clubs he has played for without problems. It is also believed that although Ba joined on a free transfer his agents were paid around £2 million in fees by Newcastle. Ba has told the club he will stay for now and the most likely scenario is for Newcastle to offer him a pay rise in return for the removal of the release clause which might enable them to keep the player at the Sports Direct Arena for longer. Ba scored what Sir Alex Ferguson described as a "magnificent" opening goal in Newcastle's stunning 3-0 victory over Manchester United last week. Indeed few will argue with the Twitter message posted by Arsenal's Jack Wilshere in the wake of that game. "Demba Ba best signing of the season!" he wrote and Ba now has 22 goals in 27 starts in the Premier League for West Ham and Newcastle. Last week Ba was named the league's player of the month and United are now one of the club's on his trail although Spurs are pushing harder for a deal, especially if they can offload Roman Pavlyuchenko. Over the weekend Ba gave an interview to the French radio station RMC in which he said it was possible he would join Paris St Germain in the summer. "I have always supported PSG and it's an attractive club," he said. But it will be difficult to do that in January. I'm in Newcastle and the fans like me. The transfer market will be closed when I return from the Africa Cup of Nations so I won't focus on it.