By Stephen English

Casey Stoner, who will retire from MotoGP after Sunday's Valencia season finale, continues to feel the effects of his hefty Indianapolis crash witꦆh the Austra෴lian admitting that he still lacks flexibility in his ankle.

His home dominance at Phillip Island notwithstanding,𝐆💝 it was clear after the opening day of practice that the very different demands of Valencia are presenting Stoner with a challenge this weekend.

Phillip Island is filled with high-speed left hand corners𒁃, whereas Valencia has a🔯 host of low-speed right hand turns that place a premium on a rider's ability to shift his weight and anchor the bike.

For Stoner this has presented a huge challenge, with the double 💙champion admitting as much after the end of opening practice:

"The foot feels average at the moment and in the wet conditions it wasn't good today," said Stoner, who missed three events afte𝓡r unde🅺rgoing ankle surgery.

"I s🅠till can't ge👍t the flexibility required in the right corners.

"At Philip Island there's only two corners that we nജeed to get over the right h൩and side of the bike.

"Here t꧟here's a few points that I couldn't get offꦿ the inside enough so it was a bit difficult but I didn't push hard this morning."

Stoner was tenth in wet morning practice and then didn't record a lap ♏time in the drying afternoon session.