(CNN) -- Perhaps the most frightening scenario facing Manchester United is that however bad this season has been, it could get a whole lot worse.
Embarrassed by great rival Liverpool on Sunday, light years behind in the race for the English Premier League title and on the cusp of European humiliation, it has been a year to forget for those so used to success.
Since Alex Ferguson stepped aside after winning the club's 20th league title, his replacement David Moyes has presided over one of the most painful periods in the club's recent history.
On Wednesday, the nadir awaits -- the possibility of exiting the Champions League at the last-16 stage to Greek side Olympiakos.
Without a massive turnaround in domestic fortunes, the three-time European champion will not qualify for the continent's top club competition next season unless it wins this year's edition -- a task which looks improbable given recent performances.
Not since 1995-96 has United failed to qualify for the Champions League -- but that reality could soon come to fruition.
Olympiakos will arrive at Old Trafford in confident mood after winning the first leg 2-0, according to the visiting team's adviser Christian Karembeu.
Karembeu, who won the Champions League on two occasions as a player with Real Madrid, says the runaway Greek Super League leader is relishing the opportunity of causing a big upset.
"The first victory was a revolution and everyone was talking about us and it made a big impact," the 1998 World Cup winner told CNN.
"For us it is already a big step we have made and we are proud of what we've done.
"I used to tell the team that nothing is easy and it's not done yet because it's going to be tough at Old Trafford.
"It's going to be dangerous but we have to focus on what we've done, what we can do better, and hopefully we can repeat those performances."
United, which has won all three home matches in this year's Champions League, lost in the round of 16 last season after being beaten at Old Trafford by Real Madrid.
Olympiakos is aiming to make the last eight for the first time since 1999, and with the domestic title already wrapped up, a foray into the later stages of the Champions League would provide some extra end-of-season excitement.
Not that Karembeu is getting ahead of himself -- Olympiakos has never won at Old Trafford and managed just one away victory in qualifying for the knockout stage.
"Manchester United is a big, famous club but that was only the first battle," the former France international said.
"The foundation and philosophy is still there but it's normal there are many changes.
"Hopefully United will stay like that but I think they'll come back again."