UPDATE 1-Soccer-Ronaldinho doubtful for Real Madrid clash

(updates after scan results)

MADRID, March 8 (Reuters) - Barcelona forward Ronaldinho is doubtful for Saturday's clash with arch-rivals Real Madrid at the Nou Camp because of muscle problems sustained in Tuesday's Champions League away goals defeat against Liverpool.

Club doctors said that a scan had ruled out a muscle tear, but added that the Brazilian would follow a special training programme on Friday to determine whether or not he would be ready to play against Real.

Ronaldinho is Barca's leading scorer this season with 17 league goals and has produced some outstanding performances against Real in the past.

Barca will also be without French winger Ludovic Giuly and Italy full back Gianluca Zambrotta who are suspended after being sent off in last weekend's 2-1 defeat at title rivals Sevilla.