The star-striker sprained his ankle during Monday's first training session with new boss Gianfranco Zola and looks set to miss the next four weeks of action.
The man made of glass would have been hoping to impress his new boss and was all set to partner Craig Bellamy in attack against
Ashton told 'the Sun', "Unfortunately I've picked up another injury.
"I sprained my ankle in training on Monday and I'm looking at spending the next three to four weeks on the sidelines.
"I just went over on it. It happens to a lot of players.
"It's not too serious but it will take a few weeks to heal properly.
"I'm looking at about three weeks and then it's the international break. Hopefully I'll be back after that."