Monaco face an uphill struggle next week in the second leg of their Champions League play-off after going down 1-0 at home to Benfica.
Vangelis Pavlidis scored his sixth goal in the competition in the 49th minute at the Stade Louis II on Wednesday night to give the Portuguese outfit the advantage ahead of the return leg at the Estadio da Luz in Lisbon on Tuesday night.
Monaco hampered their chances of a comeback when midfielder Moatasem al-Musrati was sent off in the 52nd minute.
The 28-year-old Libyan gestured to the referee Maurizio Mariani to book Benfica's Alvaro Carreras for a crude challenge on the Monaco striker Breel Embolo.
But Mariani sanctioned al-Musrati for his impertienece and, having already been booked, he was ordered from the field.
"It’s only 1-0 to Benfica so anything is still possible," said Monaco boss Adi Hütter. "We'll go there and we’ll do our best. I liked our first 30-35 minutes, where we were on the same level as Benfica."
As well as al-Musrati's absence, Monaco will be without skipper Denis Zakaria who picked up a yellow card and will be suspended for the return leg.
"We have solutions in the squad to compensate for the various suspensions," added Hütter. "Denis’s booking was really harsh, because he was completely focused on the ball. It’s a difficult decision, but we have to accept it. We are guilty of having conceded this defeat and not having defended well enough on the goal."
Having started their Champions League campaign with a win over Barcelona in September, Monaco have suffered four defeats in their last five European outings.
Elsewhere in Wednesday's first leg ties in the play-offs, Club Brugge beat Atalanta 2-1 and Bayern Munich won by the same score at Celtic. Feyenoord edged past AC Milan 1-0.
