Braga reached this stage of the competition by ousting Ferencváros and Real Betis, while Freiburg got the better of Genk and Celta in previous bouts.
Match Replays
Familiar foes square off in continental play, as Aston Villa head to The City Ground to face Nottingham Forest in an all-Premier League semi-final.
Real Betis will try to lean on their home advantage to advance after the two outfits shared the spoils with a 1-1 result in Braga in the first leg.
Porto and Nottingham Forest are level as they gear up to meet at The City Ground with a berth in the UEFA Europa League semi-finals on the line.
Aston Villa return home searching to maintain the two-goal lead they built on the road against Bologna and punch their ticket to the semi-finals.
Freiburg look to maintain their massive 3-0 lead as they head to Spain to take on Celta for a spot in the UEFA Europa League semi-finals.
Nottingham Forest ousted Fenerbahçe and Midtjylland, while Porto defeated Stuttgart to set up this bout, which will begin at Estadio do Dragão.
Strong sides collide at the Stadio Renato Dall'Ara in the first leg of the UEFA Europa League Round of Eight, as Bologna welcome Aston Villa.
Spain and Germany meet in the UEFA Europa League quarter-finals, with Celta traveling to square off against Freiburg at the Europa-Park Stadion.
Braga bested Ferencváros and will host the first leg of their matchup against Real Betis, which eliminated Panathinaikos, in the Round of 16.
Aston Villa have to simply hold strong to make it to the UEFA Europa League quarter-finals after defeating Lille one-nil on the road.
Bologna and Roma are level following a one-one draw in the opening leg in Emilia, as the guests managed to respond after going down in the score.