The play-off round is upon us and while the Barcelonas and Bayern Munichs of the footballing world have already sealed their places in the group stages, there is still plenty worth keeping an eye on as teams vie for a shot at European glory.
On the opening day of the round Manchester City took care of business in their punishing 5-0 victory over Romanian side Steaua Bucuresti, FC Copenhagen beat APOEL FC 1-0 and Dinamo Zagreb and Red Bull Salzburg scored a goal apiece in their 1-1 draw.
There are still plenty of matches to come featuring an array of teams, from Celtic and Roma through to League of Ireland chmampions Dundalk and Israel's Hapoel Be'er Sheva.
Ludogorets Razgrad v Viktoria Plzen
Taking place in Sofia, Hungary, this match-up sees Hungarian First League champions take on Czech First League winners Viktoria Plzen with each team having had recent history in the group stages of the UCL.
Led by Hungary captain Svetoslav Dyakov, Ludogorets most recent appearance during 2014-2015 where despite placing fourth they did manage a 1-0 win against Switzerland's FC Basel in a group that included Liverpool and Real Madrid.
Vikrotia Plzen last played in the group stages in 2013-2014 where they too managed a win against a more-fancied opponent, beating CSKA Moscow 2-1.
Celtic v Hapoel Be'er Sheva
After falling to Malmo at the same stage last season, the Scottish champions have failed to qualify for the competition for three years, a streak that new manager Brendan Rodgers says his side is keen to end.
The recent acquisitions of Scott Sinclair and Moussa Dembele have been in fine form in the early stages of the season and Celtic fans will expect nothing short of an emphatic victory over a Hapoel side that will be seeking to make the group stages of the competition for the first time in its' history.
After surprising Olympiacos in the third qualifying round with an aggregate 1-0 win, a win over Celtic is not out of reach of the unfancied club.
Dundalk v Legia Warsaw
Dundalk host the first game against Poland's Legia Warsaw having already achieved their best result in Europe after advancing to the third round, but will have their work cut out for them against the Ekstraklasa champions.
Legia have gone as far as the semi-finals of the European Cup in 1970, whilst their recent history has been solid, making the group stages of the Europa League in 2015-2016.
Host to a number of international representatives, including Mihail Aleksandrov of Bulgaria and Nemanja Nikolic of Hungary, in addition to a number of Polish internationals, Legia will be looking to utilise their talent to progress to the group stages for the first time since 1995-1996.
Porto v Roma
Two of the more renowned teams seeking to progress, fans of both sides will be hugely disappointed if their club fails to get through.
With Francesco Totti signing on for what many believe will be his last season with I Giallorossi, many in the footballing world are hoping to see the King of Rome have the chance to make a run at European glory.
Standing in their way are a Porto side that finished a mediocre third in the Primeira Liga last season. Led by Hector Herrera, the squad features Euro winner Danilo Pereira and Iker Casillas who will start the season as the number one keeper after stalwart Helton had his contract terminated after 11 seasons.
Villarreal v Monaco
Another intriguing series that sees two well-regarded teams fight for a spot in the group stages, Villarreal have made a number of signings during the transfer period as they hope better their best effort in the UCL that saw them reach the semi-finals in 2005-2006.
Alexandre Pato and Denis Cheryshev are among the players added to a squad that finished fourth in La Liga last season.
Monaco meanwhile have somewhat abandoned their big spending and will be relying on a return to form from Radamel Falcao in a side that features Joao Moutinho, Vagner Love and Danijel Subasic.