The Macedonia international, who is out of favour at The Hawthorns, is hopeful of joining the Trotters before their Championship game at Millwall on Saturday.
The move looks likely to go ahead despite a dramatic 11th-hour hitch last night that saw Popov return to the West Midlands from the Bolton training ground.
The Baggies agreed a loan with Wanderers for the 29-year-old but, with Popov already on loan at The Hawthorns from Dynamo Kiev, the Premier League and Football League refused to sanction the transfer.
However, further talks have taken place today and the clubs are now confident they can complete the deal.
Popov had travelled to Lancashire to complete the move but was forced to board a train back to the Midlands when it did not go ahead.
The hitch was caused by regulations stating Football League sides can only loan players from English clubs outside the transfer window.
Bolton argued they were loaning Popov from Albion but the authorities were concerned he was technically being loaned from his Ukranian parent club.
The parties now appear to have made headway through the legal minefield and Popov should complete the move this week, although the Trotters had hoped to have him in their team for tonight’s home game against Burnley.
They have been without a recognised left-back since Marc Tierney broke his leg in October.
Popov returned to The Hawthorns last summer for a second season-long loan but has made just two Premier League appearances, the last of which was an error-strewn game in the 2-2 draw with Villa at The Hawthorns in Novemver.
He has not figured in a matchday squad under new boss Pepe Mel.
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