Uncapped backs Grayson Hart and Mark Bennett will join the Scotland squad in Houston, Texas today ahead of Saturday’s opening summer Test against the USA (kick-off 7.30pm local time).The pair are replacements for Glasgow Warriors scrum-half Chris Cusiter (head knock) and centre Alex Dunbar (hip), who were injured in last night’s RaboDirect PRO12 Grand Final against Leinster.The injured players will remain in Scotland for further assessment.