Mourinho and Guardiola are both bidding to win the Champions League for a third time, with Man Utd and Man City both priced at 11/1 in the betting, ahead of Antonio Conte's Chelsea (18/1), Klopp's Liverpool (22/1), and Mauricio Pochettino's Tottenham (40/1).
Pochettino's side failed to make it past the group stage of Europe's elite club competition last season.
They are one season wiser this year but have also been handed a far tougher draw that, as well as Dortmund, includes reigning champions Real Madrid in Group H.
In similar circumstances, defending champions, Real Madrid will be aiming to be the first club to achieve a three straight win since the feat of Germany's Bayern Munich in the 1970s.
Meanwhile, CSKA Moscow will look to improve their European records after finishing last in their group in each of the last four seasons, including one that contained United in 2015.
Fresh from a 5-0 hammering at the hands of Manchester City, Liverpool is seeking revenge for its defeat to Sevilla in the 2016 Europa League final when Champions League football returns to Anfield for the first time in three years.
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However, there was little time for preparation, and therefore for the upcoming fight Mourinho will certainly add to the team. It's more comparable to the style of the Portuguese league.
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"It's a very important day for me, much more important than you can imagine".
No manager has won the Champions League three times in succession so Zinedine Zidane will be out to make history, and has the competition's record goalscorer Cristiano Ronaldo available despite serving a domestic ban. There is no need to adapt to the Champions League but he needs a little bit of time to adapt to the Premier League. I am very happy to see him on the pitch again. They beat Italian rivals Juventus last season 3-1 at Cardiff in the final.
"The Champions League is a big stage, all the best players in Europe, if not the world are here, and to be the best you have to produce your best against the best".
"Last season was our first experience of the Champions League". Olympiakos and Sporting are regular qualifiers but rarely advance, with Sporting weakened by the recent sale of midfielder Adrien Silva to Leicester. Still, Napoli were one of the more hard opponents for City. Feyenoord returns to the group stage after a 15-year absence and is likely to face a steep learning curve.
With at least five credible title contenders in the Premier League it is a tall order for anyone to succeed at home and overseas - even Pep Guardiola and his well-resourced Manchester City side ended up empty handed last season - and for a club such as Spurs, frustratingly close to a first table-topping finish in over half a century, it is easy to see how Europe can be a distraction.
Leipzig didn't even exist then - the club was created in 2009 - and is a newcomer at this level. PSG is one of five clubs to reach the knockout stage in each of the previous five seasons, along with Arsenal, Barcelona, Bayern and Real Madrid. APOEL famously reached the quarterfinals in 2012 against the odds.