Yep. That's what I did with St. Louis in MFN-1. Took over this team during the playoffs after they had gone 1-15. Last year we improved to 9-7, and this year we're winning it all baby!
Not one of my teams in MFN1,2 or 6 were playoff contenders and I have built them into decent teams. Personally i think what a lot of new owners do is try and make trades to instantly improve your teams instead of working the draft in the first couple seasons. I dont think I can stress it enough to use your early picks instead of trading them away for veteran talent. FA is also a way to work those teams. You need to be aggressive tho if you have lots of cap space