The influential midfielder was forced to come off with a calf problem in the 2-1 victory against Sporting Lisbon last night in the Europa League round of 32 first-leg match.

Moyes will be looking for good news especially as they are light in that department.

Marouane Fellaini, such a key figure this season, is out for the rest of the campaign as he needs ankle surgery.

Moyes said: "Cahill may have a calf strain, we're not sure of the severity yet."

The Scot is still bristling at the challenge on Fellaini from Liverpool's Sotirios Kyrgiakos, who was sent off in the derby, that ended the Belgian's season prematurely.

"It was a terrible tackle, " said Moyes. "We have lost a few players to tackles. It is a blow to us as Marouane will be out for a while."

While Moyes was angered at the way they let Sporting back into the tie last night he is convinced they can complete the job in Portugal a week tomorrow.

Steven Pienaar and Sylvain Distin gave Everton a two-goal cushion but Miguel Veloso found the target from the penalty spot with three minutes remaining.

French defender Distin was sent off in the incident after hauling back Liedson as he tried to break clear and that away goal could prove vital.

Moyes remains bullish and said: "I think we have seen enough to know we can beat Sporting (in Lisbon).

"But obviously I am disappointed as we had a chance to get quite well forward in the tie."

Distin will miss the return match next week as he is suspended and with John Heitinga ineligible, Philippe Senderos looks certain to be drafted in provided he shrugs off a back injury.

Pienaar enjoyed his goal but like Moyes was left frustrated at giving Sporting a glimmer of hope.

He said: "After all the hard work we did, to concede a goal is tough. Our aim was not to concede.

"It's unfortunate we have to go to Lisbon knowing they have a goal and it is going to be game on now."

"It was a nice counter attacking goal. Tim (Cahill) heard my shout and I was a bit lucky as I touched it right."

On-loan winger Landon Donovan claimed Everton are still in the driving seat.

He said: "If anything we were a little complacent, we had chances to get the third and if we'd got that the tie would be over. It is going to be difficult but we still won and are in control.

"We feel we are good enough to beat Sporting. Playing there is going to be a different story and that's why it is unfortunate to give up a goal but they still have to score."