England coach Andy Flower has said that he is encouraged by pictures posted on Twitter of Kevin Pietersen in batting action.

The 32-year-old has been out with a knee injury since March and was initially expected to miss six to eight weeks.

However, his recovery has has taken longer than expected, casting doubt on his participation in the first Ashes Test at Trent Bridge.

The pictures have delivered a timely boost for Flower, who is now optimistic that the South African-born batsman will be available when the series kicks off on July 10.

"We are thinking optimistically about Kevin's injury improving and it's nice that he's pain free," the 45-year-old told Sky Sports News. "That is great news for him and for us.

"Kevin's a really special player and we want him back as soon as he's fit enough to be back. [Seeing him bat] is good news for us and hopefully his improvement graph will carry on in the same way."

Pietersen will miss the upcoming Champions Trophy.