Sunderland boss Roy Keane's hopes of getting his side's Barclays Premier League campaign back on track have been hit by a double injury blow. The Black Cats face Reading on Saturday desperate to end a run of four successive defeats which included an embarrassing Carling Cup exit to Luton. A spirited display in a 1-0 reverse at Manchester United last time out went some way towards restoring confidence but Keane must now plan without two key players. It was revealed today that £5.5million signing Kieran Richardson could be sidelined for up to three months with a stress fracture of the back. And to compound matters, fellow winger Carlos Edwards will also be out of action for several more weeks after suffering a second hamstring tear to the one which forced him to sit out those four defeats. Keane said: 'We have had bad news on Kieran. He saw a specialist this week and he has a stress fracture of his back. We will have more news after he sees a surgeon later today. 'I would have thought that he will be out for two to three months. 'It's a major disappointment. Kieran was able to do elements of training but it affected him when he twisted or hit the ball hard. 'In the last week or two, we were hoping that it might settle down, but clearly it's a lot more serious.' Former Manchester United player Richardson, 22, has made only three appearances for his new club and may now not add to that until December. The loss of 28-year-old Edwards is also a major blow for Keane, who saw the Trinidad and Tobago international inject real pace and goals into the club's Coca-Cola Championship title charge last season. He initially damaged his hamstring in the 2-2 draw at Birmingham four days into the campaign, and has not played since. Edwards returned to training but broke down once again last week and is now facing a fresh spell in the treatment room. Keane told the club's official website: 'It's not the same injury, but it's a similar type of injury in the same area. 'It's a setback for the lad and for us because he's a big player for us. 'It's the downside with hamstring injuries. We look at injuries, we look at players' recovery, but one thing we don't do is push them too much. It's just one of those things. 'He had a week's running with the medical staff and then he trained with us. He was doing okay and then he walked off saying he felt something. It's a blow.' Today's news simply adds to Keane's injury woes after a difficult start to the season. Skipper Dean Whitehead is out for six months with knee ligament damage, while defender Paul McShane has battled his way through head and shoulder problems among a series of minor injuries to other members of the squad. Keane, who recruited 12 new faces during the transfer window, recently admitted that he now had a better understanding of the problems managers sometimes face. He said: 'When I was a player, I used to hear managers talk about injuries and I used to be quite critical of them. I used to say, 'You need to get on with it'. 'But our injuries to such important players have been a real setback to us, I have to say. 'Having said that, it gives other players an opportunity they have got to go and take.'