Dyer has endured a nightmare season at St James' Park

Dyer suffered the injury during the FA Cup win over Southampton on Saturday - his first start for about six months.

"We are positive that in no longer than three weeks Kieron will be training again," said manager Glenn Roeder.

Titus Bramble is also out for three weeks after limping out of Wednesday's 0-0 draw with Charlton.

Bramble - one of only four fit first-team defenders - suffered a hamstring strain in the second half against the Addicks.

Dyer was suffering from fatigue after playing 76 minutes against the Saints on Sunday, but it later emerged that he had a more worrying problem.

Roeder said: "Seventy-odd minutes might have just tested Kieron a little bit too much and tiredness has caught him out.

There's every chance Titus could be out there again playing within three weeks Glenn Roeder

"At the moment there isn't a major concern that, with the scan showing a very mild strain.

"Because it's Kieron, you can never put an absolute definite date on it, but we the important thing is we are keeping Kieron positive and he is keeping himself positive."

Bramble went off 10 minutes after half-time on Wednesday and Roeder added: "Titus felt a sharp pain in his hamstring, but at this moment, the physio could not give you an accurate assessment of his condition.

"He's having it iced and it needs to cool down overnight and we will have a look at it on Thursday, and he will probably end up having a scan in about two days' time.

"The physio is hopeful in the way Titus is talking to him that it will be a very, very small tear rather than something major.