Dates and times for these fixtures will be announced in due course
Shelbourne will host Crystal Palace in the league phase of the Conference League.
Joey O'Brien's side's other home games will be against Kosovo's Drita, and Hacken of Sweden.
While their away fixtures will see the Reds face Shkendija in Macedonia, Slovenia's Celje and Dutch club AZ Alkmaar.
Shamrock Rovers matches in Tallaght will be against Shakhtar Donetsk, Celje and Malta's Hamrun Spartans.
The Hoops will travel to Sparta Prague, AEK Athens of Greece and Iceland's Breidablik.
Dates and times for these fixtures will be announced in due course.

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