A couple months ago, we reported on Rangers RHP Kumar Rocker's Bowman Chrome 1st cards as solid buys due to his rise in the minors and potential call-up in September. Sure enough, our very own Lefty McKee nailed this one, as Rocker got the call-up recently to make his MLB debut, and his cards rose in value.

Additionally, consistently throughout the year, we talk and write about getting your football cards ready to sell in the first four weeks of September. The first few weeks of the NFL season are always full of surprises, and while some of the following players could continue to perform well, historical data tells us that these early season performance spikes for RBs and WRs give the best opportunity to get the highest return on card value.

Due to underperformance or even injury risk, now is a great time to list the following players...