Ramiro Funes Mori, Everton's most expensive signing of the transfer window, could make his Premier League debut against Chelsea on Saturday if Brendan Galloway or Bryan Oviedo are not fully fit, manager Roberto Martinez said.
Galloway was forced off with a knee injury during Everton's 2-0 loss to Manchester City on Aug. 23, but the Everton manager is hopefully that the 19-year-old will be available for selection against the champions at Goodison Park.
Oviedo, however, is more of a doubt after he pulled out of Costa Rica's recent friendly against Uruguay with a knee injury.
"I think Brendan is progressing well and should be available, in the same way that Ramiro Funes Mori could become available," Martinez said.
Oviedo made his first appearance of the season against Watford on August 8 after recovering from a broken bone in his foot that had kept him out of action since April.
Martinez said he was not sure how long the left-back's latest setback would keep him out of the side.
"With Bryan, it's difficult. I don't know if the weekend is too early or not - we'll find out over the next 48 hours," the manager said, adding that Funes Mori would have no problem slotting in.
"He (Funes Mori) is someone that has played in that position before. Being a left-footed defender, he has played in those positions," Martinez said.
The Argentine joined Everton for a reported £9.5million from River Plate in the summer and Martinez said the versatile 24-year-old could also feature as a central defender.
"The way I see Ramiro, he is able to play in any of those positions when he is needed, so in that respect it is about assessing how he feels."
The defender is due to rejoin the squad after completing his international duties with Argentina, who drew 2-2 with Mexico in the United States on Wednesday.
"It's a long journey coming back on Thursday morning and we'll assess that from a physical point of view," Martinez said.