Jose Mourinho's future as Chelsea manager could be on the line when his former club Porto arrive at Stamford Bridge on Champions League matchday six.
Group G is poised for a dramatic finale on Wednesday, with Porto and Chelsea tied on 10 points at the top - the Portuguese side edging their English rivals thanks to a 2-1 win in the reverse fixture.
Should the Primeira Liga powerhouse earn all three points and Dynamo also triumph, Chelsea must make do with UEFA's second-tier club competition.
Roberto Di Matteo, having orchestrated an unlikely Champions League triumph in 2011-12, paid the ultimate price for his failure to prolong Chelsea's defence of the trophy a season later, receiving the sack in November 2012.
Mourinho himself is well acquainted with the potential cost of failure in Europe. The Portuguese manager's first spell in charge came to an end when the team opened their 2007-08 Champions League group stage campaign with a 1-1 draw at home to Rosenborg.
That parting of the ways may well have had more to do with a breakdown in Mourinho's relationship with owner Roman Abramovich than on-field performance.
Indeed, all was not lost in continental competition, as Mourinho's replacement Avram Grant then guided Chelsea agonisingly close to Champions League glory, losing the final on penalties to Manchester United.
Chelsea's results this season have been significantly worse than the run which prompted Mourinho's departure eight years ago.
The likelihood that Chelsea will fail to qualify for next season's competition through the Premier League makes it particularly important for Mourinho's men to stay alive as long as possible this term.
