Jon Flanagan is facing a Rangers injury sweat after undergoing hernia surgery for the second time this season.
The 26-year-old missed the first three weeks of the campaign after having a similar operation and is set for another spell on the sidelines.
Flanagan has enjoyed a strong start to the season and manager Steven Gerrard namechecked the full-back as the only player who earned a pass mark in Sunday's 2-0 defeat to Celtic.
But the one-time England international faces an anxious wait to discover how long he will miss after the latest procedure on Monday - report the Daily Mail.
The former Liverpool star has been playing regularly at left-back and his absence could lead to an extended run in the first team for Borna Barisic.
The Croat has struggled to make a telling impact since his £2m move from Osijek last summer but did net in the win against St Mirren earlier this month. Andy Halliday is another option.
But it's better news on the injury front for Rangers with Jordan Jones set to only miss a month after scans revealed the Northern Ireland international did not suffer ligament damage against the Hoops.
The winger scythed down Moritz Bauer in stoppage time and left referee Bobby Madden no choice but to send him off.
Jones hobbled down the tunnel and is dealing with severe swelling after his moment of madness.
