The hold-up appears to be purely down to logistical issues in terms of sitting down to discuss personal terms.
The Birmingham Mail report the transfer is likely to be concluded over the weekend, stating: "A deal for Wigan’s James McClean remains in place with a successful conclusion to the £1.5 million transfer expected over the weekend once the various parties can get around a table."
McClean has been on international duty with Ireland over the past week, although his country's fixtures for the summer have now concluded.
West Brom have been linked with a number of wingers, with The Sun reporting earlier this week they remain keen on QPR's Matt Phillips, but been knocked back by Nottingham Forest regarding Michail Antonio.
HITC also understand the Baggies are one of the clubs monitoring Reading's for-sale winger Hal Robson-Kanu.
The hold-up regarding McClean provides an opportunity for rival clubs to steal in and make a late offer, and mindful of this, it is likely West Brom will not wait too long before hurrying up a meeting for which to get McClean signed, followed by a potential medical early next week.