The 26-year-old withdrew from the national team squad last week for the matches against Czech Republic and Scotland due to the injury and he is waiting on the results of a scan to see if he can face Sporting.
He said on his club's website: "The feelings are very good but we need to wait for the scan to see the state of the injury.
"I'm a player who can play with pain, but this is a delicate area. But if nothing shows up in Thursday's scan then I'm going to try and play."
Missing the Spain matches was a blow for the former Real Madrid striker as he tries to earn himself a place in next year's Euro 2012 squad, but he hopes good club form will keep him at the forefront of Vicente del Bosque's plans.
"There's a long way to go, it's all related to doing things well with my team and then when the (Spain) coach gives you a chance, continue working along the line that I'm following which I think is correct," he said.
"Now I have to maintain my level, make it difficult for the national team coach. The European Championships is a train that is far off but I will do everything possible to be on it."