Laurent Blanc feels Paris Saint-Germain have not yet recovered from their dramatic UEFA Champions League exit to Chelsea last week.
Demba Ba struck three minutes from time at Stamford Bridge last Tuesday to ensure Chelsea a 2-0 win on the night and a passage to the semi-finals on away goals.
The result sent PSG crashing out of Europe's premier club competition at the last-eight stage for the second season in a row, and the Ligue 1 leaders' week went from bad to worse on Sunday when they were beaten 1-0 by Lyon in a dress rehearsal for Saturday's Coupe de la Ligue final.
Jordan Ferri scored 31 minutes in to ensure a frustrating night for the reigning champions, who still lead the French top flight by 10 points from Monaco.
And coach Blanc believes the defeat in west London is still on his players' minds.
"We haven't fully overcome the loss to Chelsea," he told the club's official website.
"But we still had opportunities to win (on Sunday), especially in the second half. We struggled to put the ball away.
"The problem wasn't physical, but rather in the players' heads.
"We will get back to work now to prepare as well as possible for (Saturday's) final of the Coupe de la Ligue against Lyon."comments