Dwight Howard -- Mum's the Word on Lakers Trade

Dwight Howard had nothing to say when we asked him about the rumored blockbuster trade that would send him to the L.A. Lakers ... well, actually he has a lot to say ... but he's being muzzled.

TMZ has confirmed with sources familiar with the situation ... Dwight is in "serious negotiations" to become a Laker in a trade involving 4 teams ... and it could happen VERY soon.

If the deal actually goes through, it would send Andrew Bynum packing ... possibly to Philadelphia.

Moments ago, our photog found Dwight in L.A., where he's still recovering from back surgery ... and asked the NBA star about all the wheeling and dealing.

Dwight pursed his lips at the question (pun intended) -- but with millions of dollars on the line ... it's probably a smart move.