The Spaniard entered qualifying eyeing a second row grid position but said that after Q1 he "realised that we were not going to be as competitive as we thought".
Alonso, 27, lines up eighth on the grid for his second home race of the season, but Germany's Auto Motor und Sport claims he was slowed by a factory defect in his brakes that was only discovered after qualifying.
"Without the problem Fernando could have been on pole position," team boss Briatore said.
Alonso confirmed that he tackled qualifying with less than ideal brake bias settings, because the fronts were constantly locking up.
