Maitland injured his ankle ligaments in Saracens' Aviva Premiership loss to Wasps on Saturday 6 May.
Consequently, Gregor Townsend has called up the Glasgow winger and London Irish full-back Greig Tonks to his first squad as head coach.
Scotland face Italy, Australia and Fiji in their trio of June Tests.
Rory has won two Scotland caps, the most recent of which came in the November win over Georgia.
Gregor said: "Rory [Hughes] has had a really good season. He was on excellent form before the injury he suffered just before Christmas and got back to that form towards the end of the season.
"This is an opportunity for him to continue the good work he put in this season, in particular leading up to the autumn tests, where he was capped against Georgia."
Scotland tackle the Azzurri in Singapore on Saturday 10 June, before taking on Australia in Sydney seven days later, and complete their summer programme in the Fijian capital Suva on 24 June.