It has been an odd season so far for the 43-year-old: more competitive than the past two years but caught up in incidents, penalties and bad luck and with only 2 points on the board.
It has revved up speculation about the great German's future, but so far neither side has been willing to talk about it.
"We need to analyse the start of the season very carefully," team boss Brawn told Germany's Sport Bild.
"We have not reached our goals with Michael. It was not about the car and Michael being too slow, it's just been a few unfortunate circumstances coming together."
The Briton hinted that Schumacher's future is in his hands.
"After his accident in Barcelona, Michael was very unhappy, but after qualifying in Monaco he was very happy," Brawn smiled.
"I think basically the positive feelings outweight the negative this season."
He indicated that Mercedes is convinced of Schumacher's talent and value.
"With the pole position, Michael showed what he is still capable of, so there is no reason for us to not want to continue with him."
Brawn said therefore that, later this season, "if we achieve our goals together with him, he like us will probably be interested in going on".
"If we all feel that it is right to continue, it will happen," he insisted.
If Schumacher does, however, decide to return to retirement, there is speculation Paul di Resta is at the front of the queue.
"We have no real plan B," insisted Brawn, "although one or two people have asked us about our situation for 2013."