Dominic Calvert-Lewin will not be part of the Everton squad to take on Chelsea on Saturday after 'feeling something' in training.
The Toffees are desperately short of options up front but Calvert-Lewin's absence with a hamstring problem that has dogged him all season will extend at least until after the international break.
The England forward has made only 12 appearances all season, the last of which came in the victory over Arsenal in early February.
Manager Sean Dyche denied Calvert-Lewin had suffered a setback, saying: "He's just felt something that we've had to be careful with.
"We're still monitoring the situation, being careful, he's being careful with his body. We're trying to give him every opportunity.
"He wasn't overly in my thinking for the Chelsea game regardless of anything else because obviously the international break comes and you can hopefully use that even more wisely.
"We're trying to get him as strong as he was two years ago and get him back to that statistical level as well. I just want to get him out there training every day and feel good about that, that's the best start point and we'll take it from there."
Dyche, meanwhile, will wait until the international break to talk to Dele Alli, who has struggled on loan at Besiktas and appears to have been frozen out by the Turkish side.
"The news is suggesting that he's not going to be involved there so I'll wait and find out during the international break," said Dyche.
As for Alli's Everton future, the Toffees boss added: "We'll have to wait and see and judge things probably in the summer now when we all get back together."
Defender Conor Coady missed out on inclusion in the England squad on Thursday after losing his place in the Everton side in recent weeks to Michael Keane.
"He's been an immaculate professional, which everyone knows, or everyone in the game has always suggested and now, having worked with him, I can see why," said Dyche.
"The fine margins of football and who to play for what reasons, I just made a call on it, that was all. But he's a high-quality footballer, that's for sure, fantastic attitude and a leader.
"There's a number of players who could argue the case of getting in. There's a lot of good players here that I'm trying to keep alive because things change quickly."
Victory over Brentford last weekend lifted Everton up to 15th place in the Premier League table but they are only three points clear of bottom side Southampton.
With nine teams covered by just five points, the race to avoid the drop looks set to go down to the wire.
"I only concentrate on us," said Dyche. "I'm well aware of what others are doing quite obviously, I'm aware of the table, but it's about continuing to build on what we're doing.
"We've shown strong signs of improvement in areas we thought it needed it, the shape's been good, the energy's been good, the commitment to play and to what we want to do has been good.
"We can still find better pockets of football at times but that comes with belief and confidence, and the reality is you're playing some good sides.
"Brentford got a stronger hold on the game second half but they're a good outfit and we saw it through in a different way and that's pleasing for me, finding different ways to get wins, to get points.
"These are all part of a season's work. I think we're putting the building blocks in to start that kind of feeling, when you can put wins together and back-to-back results."