Jackson, who sustained the injury whilst scoring the only try of the night, will therefore be out of contention for Glasgow's opening two Heineken Cup pool matches in October and the prospects of a debut cap during the Bank of Scotland Corporate Tests against Fiji, Australia and Argentina in November.
Glasgow Warriors team doctor, Gerry Haggerty, said: "Following medical examination on Monday evening Ruaridh will have his shoulder stabilised in the coming week once the injury has had time to settle.
"It will take around three months for the shoulder to heal but our immediate aim is to ensure a full recovery for Ruaridh and to have him back playing for Glasgow as soon as possible."
Glasgow Warriors' next game is against Llanelli Scarlets at Firhill on Sunday (13 September, kick-off 5:05pm).
Tickets for Sunday's game - priced at £15 for adults in advance with a new AnyGame voucher (£20 on match days), £10 for concessions (including students) and £5 for under 18s - can be purchased now by calling the Ticket Hotline on 0844 800 3490 or by logging onto www.glasgowwarriors.org.
Glasgow Warriors' new AnyGame Vouchers have been introduced to encourage supporters to buy early and, to avoid queues, are not for sale or collection on match days.
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