According to Geoff Leopper of the Mercury News, Barnes should be getting the start tonight:

With forward Mickael Pietrus, a starter in the Warriors' first four games, not expected back until Friday or possibly even Sunday, Warriors Coach Don Nelson said he's going to give forward Matt Barnes his first start of the season tonight against the Detroit Pistons. It would be Nelson's fourth lineup in six games.

"Matt had his best practice (of the season) today," Nelson said Tuesday. "Without Pietrus there, I really need a good performance from him. That's why I was so encouraged with today's practice. We know what he can do when he's right, and it didn't look like that hand was bothering him much."

Barnes has been steadily improving despite dislocating the ring finger on his right (shooting) hand against Cleveland on Nov. 6 and dealing with an ongoing personal issue off the court.

The article did not say whether Barnes would be starting at SF or PF, but given Harrington's play, it seems unlikely Al gets sent to the bench. A better question is whether Ellis or Azubuike will sit.

As an aside, Croshere will be back in uniform and available tonight, according to this same article. (Note: Pietrus' absence was mentioned in this diary. Speculation is that he has visa issues and had to sort that out.)