Aged 28, Rangers winger Jamie Murphy could finally win his first Scotland cap against Costa Rica.
Celtic left-back Kieran Tierney has been forced to withdraw from the Scotland squad following an injury.
Celtic's Kieran Tierney and Liverpool's Andy Robertson are Scotland's best left-backs, and Tom Boyd believes they can play together.
West Bromwich Albion's former RB Leipzig winger Oliver Burke has been omitted from Alex McLeish's senior squad and will line up for the under-21s.
Rangers defender David Bates has impressed in 2018.
Wolverhampton Wanderers left-back Barry Douglas is set to earn a Scotland call-up for the first time in his career aged 28.
Following Scott Brown's retirement, the Scotland captaincy is up for grabs, but will McLeish be willing to take a punt on Celtic youngster Kieran Tierney who has captained his country already?
What happened on this day in 2005 when Celtic played host to Rangers?
Alan Hutton is out of contract at Aston Villa this summer.
Ex-Glasgow Rangers boss Alex McLeish would have loved to see Steven Naismith go back to Ibrox.