By Julien Pretot
PARIS, Nov 26 (Reuters) - Attack-minded Paris St Germain must shift their focus to becoming a tighter defensive unit if they are to keep improving, coach Laurent Blanc said.
PSG, who will qualify for the Champions League last 16 if they at least draw at home against Olympiakos on Wednesday, have scored in every game since their last defeat, a 1-0 reverse at Stade Reims on March 2.
"We've scored goals since the start of the season, the mentality you need is not to concede any. Everyone needs this mentality, the strikers and the defenders," the former France coach told reporters on Tuesday.
"Considering how many we score, if we don't concede we have a great chance to win games."
PSG have no problem finding the back of the net with Zlatan Ibrahimovic and Edinson Cavani having scored 27 goals between them this season in the Champions League and Ligue 1.
Blanc favours a 4-3-3 system with central defenders Alex and Thiago Silva, left back Maxwell, right back Gregory van der Wiel and holding midfielder Thiago Motta keeping opponents at bay.
"Alex is always there, he doesn't draw attention to himself. He's strong in the tackle and wins a lot in the air," Blanc said.
"The (4-3-3) system is important, of course, but so is the understanding between the players.
"There is probably much more solidarity in this team than there was last season or the season before. What interests me is that we keep this solidarity and efficiency, no matter what the system is.
"Otherwise you get stuck in a system and what happens when a player can't adapt to that system? He doesn't play."
PSG top Group C with 10 points from four games and lead Olympiakos by three points with Benfica in third place on four points. Anderlecht are bottom with one point. (Reporting by Julien Pretot; Editing by XXXX)