London - Scotland manager Steve Clarke said he had omitted Kieran Tierney from the squad for their final two Euro 2020 group qualifiers because of a request from the full-back's club Arsenal.
The 22-year-old underwent a double hernia operation in the summer.
He eventually made his debut for Arsenal in the 5-0 thrashing of second tier Nottingham Forest in the League Cup on September 24.
A couple of Europa League matches followed and he has played in their last four games.
"Arsenal asked us not to select him (Tierney)," Clarke said.
"Kieran has an ongoing issue that Arsenal are keen to address in the next international break.
"It's a little bit frustrating. It's obviously frustrating for Kieran as well, but we've got good cover in that position."
Clarke would not be drawn on what the issue was.
"That's a question for Arsenal."
Tierney will miss two effectively dead rubbers - Cyprus away on 16 November then Kazakhstan at home three days later - as Scotland cannot qualify from Group I.
Clarke's side can still reach the finals via the play-offs in the spring, and he has made finishing third in the group a "minimum requirement", with Cyprus a point above his side.