Arsenal midfielder Denilson expects to have recovered from a mystery injury in time for his side's next game against Bolton Wanderers.

The Brazilian, who recently returned to action following a back problem, fell suddenly during the game against Everton last Sunday when running with the ball, with no opponent near him.

Denilson was then stretchered off, but, reflecting on the incident, said he had recovered.

"I don't remember what happened. I was just running with the ball and I felt a pain in my side. I couldn't run or stop the ball, but I feel okay now," he remarked.

However, the player noted that while confident he would be fit for the Bolton game, he was having a scan to assess what might be wrong.

Those who have back problems may find that ultrasound treatment helps to ease the difficulty.

One sportsman whose back problems may be more serious is South African cricketer Friedel de Wet.

The fast bowler has pulled out of South Africa's squad to face England in the final Test match in Johannesburg this week due to the injury, which restricted his bowling in the previous clash between the sides in Cape Town last week.