ALBION have stepped up their efforts to establish the reason for Solly March's injury absence since the start of the season.
The England under 21 international missed out for the fourth match running at Leeds last night.
Boss Sami Hyypia was hoping to have him available for the trip to Elland Road but March stayed at home for further checks on the lower back problem which has ruled him out so far.
A first scan proved inconclusive. Albion are hoping a second more detailed scan will help hasten the recovery of March, whose treatment programme so far has included acupuncture.
The 20-year-old from Eastbourne featured in more than half of Albion's Championship matches under Oscar Garcia last season.
He was awarded a four-year contract by the club in April and made his England under 21 debut alongside team-mate Jake Forster-Caskey against Qatar in the Toulon tournament in France in May.
The versatile March, forced off after starting Albion's final pre-season friendly against Southampton at the Amex last month, is likely to feature in Hyypia's attacking plans.
He can operate as an advanced midfielder or as part of the narrower front three introduced by Albion's new Finnish manager.