In the Tall Cotton?

I had a weird moment today watching the UCLA-Oregon game. The Ducks have this running back with super quick feet. It seriously looked like he was playing Dance Dance Revolution out there as a he juked and avoided two, three, even four Bruin defenders at a time. He tore up UCLA in the second half and was a big part of the victory.

After one of this guy's impressive runs, the announcers were talking about him. One of them said something like "I wouldn't say put him in the tall cotton just yet". I'd never heard this saying before or anything like it. My buddy and were perplexed, to say the least. The player in question is African American, and putting two and two we came up with "What the hell?".

I tried looking up the term later, and all I got was that "tall cotton" refers to a time a plenty (ie. when the cotton crop grows tall). I guess it sorta made sense (maybe? or not?) if he was saying that the player himself is not yet "the tall cotton" on account of his limited playing time. But that just sounds weird, and it doesn't make a lot of sense given the way the sentence was constructed.

I'm not trying to make something out of this, and I seriously doubt the announcer meant anything negative by his comment. I'm just struggling to figure out what he meant.