And he could return to the Hawthorns in little over two months' time, should he impress the Charlton manager, Lee Bowyer.
Mears and Bowyer played together at West Ham United and speaking to the South London Press, the latter confirmed: "I played with Tyrone at West Ham and he will train with us for a week.
"We will just look at him fitness-wise. He is a fit lad anyway and still quick – he was rapid when I played with him.
"He can’t be far off it."
Charlton sold Anfernee Dijksteel to Middlesbrough on the penultimate day of the summer transfer window, but failed to sign a replacement right-back in time.
But the Addicks can still add to their squad through the free agent market - providing any prospective signing was already without a club by the deadline for English Premier League and Championship clubs.
West Brom strengthened in Mears' position with Darnell Furlong, although it is the Baggies academy product, Nathan Ferguson, who has started both of their second-tier fixtures so far.
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