Mulgrew is yet to shake off the niggling knee injury that kept him out of their Champions League qualifier against Qarabag on Wednesday.
Meanwhuile, Ciftci and Izaguirre are both suspended with the former starting a six-game domestic ban.
Ciftci’s sentence was handed down while still a Dundee United player, after biting Jim McAlister during the Tayside derby last season – a further two games are suspended.
As for Izaguirre, he is banned for collecting too many disciplinary points last season.
Ross County will be without Jamie Reckord for the league opener after the former Wolverhampton Wanderers left-back suffered an Achilles problem last week.
But manager Jim McIntyre believes he now has genuine depth in his heavily re-shaped squad as he prepares the side for a fourth consecutive season in the top division.
He told the Ross-shire Journal: “The biggest thing about pre-season for me is getting through with no injuries, or as few injuries as possible.
“If you look across our back-line, we’ve got great cover. Richard Foster can play both full back positions, while Marcus Fraser can play centre-back and full-back, along with our other centre-backs. We’ve got really good flexibility there.”
Don’t miss a kick as Celtic tackle Ross County live on Sky Sports 1HD from noon on Saturday, 1 August,