Manchester United have been hit with a major blow with reports that Marcos Rojo will be sidelined "for weeks" after suffering a serious shoulder injury in training. The Argentinian defender picked up the injury in training yesterday, and was immediately sent for a scan, amid fears it could be a repeat of the dislocation he suffered against Manchester City at Old Trafford in November last year. He was out for almost a month on that occasion but didn't have surgery.

Newcastle United have been rocked by yet another injury blow after Mike Williamson picked up a hamstring issue. The centre-back had been in contention for the clash with Liverpool after being recalled from a loan spell at Wolves this week, but Steve McClaren explained the player had "tweaked" his hamstring and is ruled out of Sunday's game. Williamson had been recalled due to another hamstring injury for Jamaal Lascelles.

McClaren also confirmed that Lascelles would not be available after picking up an injury against Crystal Palace, while Cheick Tiote has not recovered from the groin problem that resulted in him being subbed against Leicester.

Sunderland will be without Jermain Defoe for Saturday's trip to Arsenal, but the striker's hamstring injury is not as serious as first feared. The 33-year-old limped off in the Black Cats' 1-0 win at Crystal Palace last month but is expected to return at home to Watford on December 12 after scans revealed he did not rupture ankle ligaments.

Jack Rodwell and Sebastian Larsson will also miss Saturday's clash at the Emirates, with the latter in Barcelona to see a specialist on his medial knee injury.

Arsenal have received another blow, with confirmation that midfielder Santi Cazorla will miss at least three months with a knee ligament problem. The Gunners are currently going through a crisis with no less than ten players injured, with the latest three coming from their draw against Norwich last weekend. Koscielny and Sanchez were both forced off the field during the game, but Cazorla played all 90 minutes despite having some pain in his knee. But now it has been confirmed that the Spain international will be sidelined until March.

Goalkeeper Artur Boruc could be facing a spell on the sidelines due to injury. The 35-year-old, who started the season as Bournemouth's first choice, returned from international duty with Poland last month nursing a knee problem. Reports in Poland claiming Boruc may need an operation, which could rule him out until the new year. Bournemouth are also awaiting news on Adam Federici who sustained an ankle injury during Saturday's 3-3 draw with Everton.

West Ham fear Diafra Sakho will be out for up to three months after picking a thigh injury in Sunday's match with West Brom. The Irons have been boosted however, by the news that Enner Valencia could be back for their Christmas programme.

Sakho pulled up with 17 minutes of the 1-1 draw left and now faces a scan this week to determine the exact length of time he will be out. Club sources are hoping it is not worse than the initial estimates, but it is understood the affected area is too badly swollen to be scanned as yet.

Manchester City striker Sergio Aguero has played down fears he is set for another lengthy spell on the sidelines, after the 27-year-old was withdrawn after 63 minutes in his side's 3-1 win over Southampton on Saturday. Aguero later used Twitter to confirm his injury was minor, while reports on Monday suggested he would be out for around 10 days. Aguero, whose prolific goalscoring exploits over recent seasons have been interspersed with regular injury lay-offs, recently returned to action following six weeks out with a hamstring problem.