Swindon have snapped up Simon Ferry and Paul Caddis from Celtic after the pair agreed personal terms on respective three-year deals.
The Robins saw a revised second bid believed to be in the region of £350,000 accepted by the Glasgow giants on Thursday, although the official price remains undisclosed.
Midfielder Ferry is already familiar with the Wiltshire club having spent last season on loan at the County Ground.
Caddis, meanwhile, made 13 appearances for Celtic during the 2009/10 campaign.
The pair, both 22, could make their debuts in Saturday's League One opener at home to Brighton.