Four-time European Champions Toulouse have hit a rough patch over the last month with a laboured win against Brive last time out their first success in four matches.
However Poitrenaud, who scored the opening try in that 30-21 victory, is well aware that Toulouse will have to raise their game ahead of this weekend's clash with third-placed Toulon.
He said: "We're going there to prepare for the semi-finals, it's an important game for us.
"Things haven't been perfect over the last few weeks, we're rebuilding our rugby little by little after losing the European Cup quarter-final [to Edinburgh] which hurt us more than we realised.
"Up against one of the main challengers for the title it will be important for us, regardless of the result, to perform better than we have in recent weeks.
"We know what we are capable of but a season is long and complicated. Sometimes you go through rough patches and you have to deal with them as well as you can.
"We're working hard in training because getting back to your best always starts with a good week's work."