Linfield will be playing their home Europa League game on either July 3 or 10 at Mourneview Park.
With Windsor Park unavailable for the tie an informal approach was made by Linfield to Glenavon to play their home game in Lurgan.
However, before the agreement was formalised it was announced by certain media outlets that Linfield were Mourneview-bound.
Glenavon chairman Adrian Teer confirmed he received an apology from Linfield chairman Jim Kerr on Monday night after the news broke. The arrangement has since been formalised.
Mr Teer said the intention had always been to formalise the deal, but a letter which was due to be sent by Linfield, never arrived.
With Glenavon also in Europe it will mean Mourneview Park will play host to two Europa League games within the first two weeks of July.