Steve Nash -- Lakers Star Involved In Bizarre Custody Fight

When L.A. Lakers star Steve Nash joined the team, he said one of the benefits was that he could be closer to his kids ... which is why his legal fight to keep his children out of California is bizarre.

Sources connected with the couple tell TMZ ... Nash's ex-wife Alejandra wants to move the former couple's three children from AZ to L.A. We're told Nash has objected and is waging a legal war to prevent it from happening.

Our sources say Alejandra hired one of the biggest divorce lawyers in L.A., Lance Spiegel, to fight Nash in both AZ and California courts.

As for why Nash doesn't want his kids moving closer to him, we called his rep but haven't heard back.

Based on our research, one thing's for sure ... Nash will get socked for WAYYY more child support in CA than AZ.

We're told there is a gag order in place ... so no one can talk about the case.

Spiegel told TMZ, "I can't comment on the information you attribute to sources connected with TMZ."