Segundo Castillo, Joseph Yobo and Victor Anichebe could all be available for Everton's Premier League clash against Manchester United at Goodison Park on Saturday.
The trio were absent from last weekend's 3-1 loss to Arsenal at Emirates Stadium but are all on course to feature versus the Red Devils.
Suspended midfielder Tim Cahill and long-term injury absentee Lars Jacobsen will miss out, but head of sports medicine Mick Rathbone is hopeful manager David Moyes will be boosted by the return of Castillo, Yobo and Anichebe.
He told the club's official website: "Segundo was injured playing for Ecuador. He came off quite early in the game so we expected a problem and he has come back with a pretty slight hamstring strain.
"He's done some light jogging now and he's going to be - hopefully - close for the weekend. We don't know yet but he's making good progress.
"Joseph Yobo's had quite a nasty virus. He's been off for five days but he trained today so hopefully he'll be able to train all week and he should be okay.
"And Victor too - he got a very minor hamstring strain in the reserve game against Liverpool (last week) but he's with Castillo now and running pretty comfortably. We'll just see how they all go for the next couple of days."
Rathbone also confirmed that towering midfielder Marouane Fellaini should be available despite suffering a dead leg versus the Gunners.
He added: "Marouane Fellaini got a dead leg and came off in the second half but that's not bad and I don't anticipate any problems with that. So it's so far, so good."