McCarthy, 28, has not played a minute of competitive football for the Blues since suffering a double leg break against the Baggies almost a year ago.
According to Sky Sports, the Irishman could join Darren Moore’s side for the rest of the season:
Understand #wbafc interested in possible loan deal for #efc midfielder James McCarthy. Hasn’t played for 12 months since broken leg - against Albion. But Moore looking for midfield cover, and Everton keen to get him game time as he steps up his recovery.— Rob Dorsett (@RobDorsettSky) January 3, 2019
McCarthy joined Everton in September 2013 from Wigan Athletic for £13 million, but has fallen down the midfield pecking order at Goodison Park, with Idrissa Gueye, André Gomes, Tom Davies and Morgan Schneiderlin all preferred by manager Marco Silva this term.
He resumed training in September, but Silva has yet to name him in a matchday squad other than November’s friendly against Gor Mahia, in which McCarthy played half an hour.
This would not be the first dealing between the two clubs during this transfer window, after West Brom signed Toffees defender Mason Holgate on loan for the rest of the campaign earlier this week.
Albion have also signed Brendan Galloway and Gareth Barry, on loan and permanently respectively, from the Blues in recent years.