Would this trade be too soon?

[StateGame23]

I have been rolling out Portis and Larry Johnson as my RB tandem, but LJ conveniently got hurt. I'm not sure how long to wait on his status because I've been doing that with Marvin Harrison all year. Playoffs start in week 14 and I'm right on the edge of making it in. Do I make this deal, or wait on LJ?

I get:
Reggie Bush
Brandon Marshall

I give:
Clinton Portis
Plaxico Burress