The Dutchman did not hesitate to substitute his outstanding countryman only minutes after he had scored the winning goal in their 1-0 victory over Olympique Lyon in the first leg of their Champions League semi-final on Wednesday.
The winger, who only seconds earlier had come agonisingly close to another goal, looked irritated and the 66,000 fans were bewildered as he walked off the pitch in the 85th minute. Van Gaal on the other hand knew exactly what he was doing.
"In three days we play Borussia Moenchengladbach (in the league) and I have to make sure that we go there with all our players fit," Van Gaal told reporters after the game.
"So now we have won here, we did not concede a goal and we will go to Gladbach with Robben fit, (Ivica) Olic fit and all my players fit," added the Dutchman, who won the Champions League in 1995 with Ajax Amsterdam.
Croat striker Olic was substituted early in the second half as the Bavarians preserve ammunition for the final stretch of the season in all three competitions.
Van Gaal, in his first season at Bayern, said months ago that he would leave if he won all three titles, which at the time seemed a fanciful notion.
They are now in complete command of the league, have advanced to the German Cup final and are in control of their Champions League fate.
"That was European Cup at its best," glowed club chairman Karl-Heinz Rummenigge. "We played a fantastic second half and will now travel to Lyon (next week) full of hope."
Few would have thought at the beginning of the season that Bayern could trigger such superlatives without Franck Ribery on the pitch.
The French midfielder saw a straight red card in the 37th minute for stamping on the ankle of forward Lisandro Lopez and will now miss the return leg.
"I hope that for Bayern and himself he will be banned for only one game," said Van Gaal, with one eye already firmly set on the Champions League final in Madrid on May 22.
