Every Wednesday, The Fantasy Doctor ponders fantasy football dilemmas and prescribes advice with an eye on helping you win. Email your fantasy questions to  fantasydoctor@pfwmedia.com. Questions may be edited for clarity.

I’ve been offered Calvin Johnson for Rob Gronkowski. I need another wideout; I have only Jordy Nelson, Malcom Floyd and Michael Crabtree. My backup tight end is Tony Gonzalez. What do you think?

— Elvis

Now this is a trade proposal I like. You know what I don't like? Trading a blue-chip player for multiple players hoping the cumulative impact will make up for the loss of an elite performer. I'm a star-for-star guy. Those deals get a league buzzing, and though I can't quantify it, I believe they are better propositions than one-for-three deals and the like. 

This looks like a fair deal to me. If you're going to trade Gronkowski, I believe you have to get a player like Johnson in return. Yes, he has scored only two TDs, but he has had a couple of monster games in a row, and he's very clearly in Pro Bowl form. 

However, here's why trading for Johnson isn't a total slam dunk: he's dealing with some persistent knee soreness. Clearly, he's shown he can thrive under these circumstances. If the condition were to get worse, or if the Lions (4-5) were to fall out of playoff contention, it's always possible that Johnson could get a little more rest than you would like down the stretch. Please note that I'm just speaking hypothetically here; in my view, though, Johnson's knee is a risk you have to consider. 

In the end, would I make this trade? If I believed Johnson would put me over the top in the next several weeks, I probably would. The presence of Gonzalez, who's having an exceptional season in his own right, would seal the deal.