Rafael Benitez's Chelsea suffered a lackluster 1-0 defeat to Steaua Bucharest in its Europa League last-16 first-leg clash at the National Arena on Thursday.
In the first of two games in four days and the Blues' 50th game of a turbulent season, last season's Champions League winners went behind after 34 minutes when Ryan Bertrand was penalized for pulling back Raul Rusescu, who converted the spot kick.
Benitez was disappointed with the penalty decision that led to his side's loss.
"I think it was very soft. To give a penalty in this situation, and especially when you have so many referees in their positions, it is soft," the Spaniard told ESPN. "You cannot change the situation but it is very soft. If you give the penalty, why not the [red] card? Strange."
Just like Sunday's opponent Manchester United, Chelsea warmed up for the FA Cup quarterfinal with a European defeat, but at least its rival was defeated by Real Madrid. The result in the Romanian capital will only serve to increase the pressure on interim manager Benitez.
Chelsea began the season in contention for seven trophies and the Europa League is the unexpected eighth after an embarrassing Champions League group stage exit which prompted Benitez's unpopular appointment.
Two chances at silverware remain, but chief executive Ron Gourlay this week insisted a top-four place in the Premier League and Champions League football next season is the priority.
It is just as well as now Chelsea must beat United and overturn a deficit to Steaua in next week's return to keep its trophy hopes alive.
Benitez thought Chelsea was the better team on the night but rued its lack of a cutting edge in the final third.
"I was a little bit disappointed because I felt we could have scored and now we have to do everything at Stamford Bridge," he said. "It will be difficult because they are quite organized, they work very hard and they can counterattack. But we have confidence that we will do well at Stamford Bridge."
Petr Cech echoed Benitez's comments, believing the Blues deserved something from the game, but the goalkeeper is confident ahead of the second leg in London next week.
"This is not the result we want to get away from home in the first leg but to be fair we had better chances than them," Cech said. "I hardly made a save all game. They had a penalty and they scored from there and they won. We're just disappointed we didn't score. We made it hard for the return leg but 1-0 is not the result you can't overcome."
John Terry would not have expected to be playing a key role in the second-tier continental competition this season, but in Bucharest the captain was brought in as one of five changes to the side that beat West Brom.
Because of his recent fitness travails, it must be questionable if the skipper will start at Old Trafford, when the Blues bid to continue their FA Cup defense.
Terry was an unused substitute in Prague in the last round, something that sparked stories of dissatisfaction which were swiftly quashed before dressing room tensions resurfaced.
Steaua, 12 points clear domestically, had shown its ability by overcoming a first-leg deficit to beat Ajax on penalties and Chelsea needed to start better than in the previous round.
An expectant partisan crowd made Benitez feel at home, jeering every time Chelsea had possession as the hosts refused to be intimidated.
Scarcely did they have reason to boo as the hosts enjoyed far superior territory and possession, including three corners in the first 15 minutes and a tame shot wide from the impressive Alexandru Chipciu.
The Blues sat deep and were attempting to play on the counterattack, with Oscar through the middle, Hazard on the left and Yossi Benayoun on the right behind lone front man Fernando Torres. However, they struggled to string three passes together on a bumpy pitch.
At one point, Torres -- who was targeted by a laser pointer in the first half -- latched on to Petr Cech's long clearance on the right flank, skipped by his marker on the byline, before tackling himself as he prepared to cross to his arriving teammates.
Left back Iasmin Latovlevici, earmarked as a danger-man by Benitez on the eve of the match, crossed with the outside of his right foot towards Rusescu, whose attempts to reach the ball were thwarted by a pull from Bertrand.
Referee Sergey Karasev booked the left back, playing in place of Ashley Cole, and Rusescu sent the resulting spot kick under Cech.
The Blues were roused into action and had a chance for an equalizer within five minutes following neat interplay between Benayoun and Hazard, but the Israeli's shot was turned around the post by Ciprian Tatarusanu.
The goalkeeper saved a Torres effort on the turn and John Obi Mikel had to be alert to stop Chipciu on the counter, with the Blues exposed.
Time and again the hosts troubled the Blues early in the second period, with David Luiz and Terry forced into some last-ditch interceptions.
A lofted Lampard pass would not drop for Torres in the area, before Juan Mata replaced Benayoun with Chelsea in desperate need of a spark.
Hazard volleyed over after a hopeful Lampard cross fell to him at the back post before the ineffective Belgian was replaced by Marko Marin, the only forward option remaining on the Blues bench.
Tatarusanu saved from Marin after he cut inside on to his right foot and Luiz fired a 30-yard free kick over soon after.
Terry's brief role as an auxiliary striker ended when he committed a foul challenging the goalkeeper -- and he finished the contest on the defensive.