Yeah, practically and logistically, it's going to be more challenging for the NFL. Bigger rosters, larger coaching staffs, more support personnel. Not saying it's impossible, but there are some serious hurdles in the way.
You can keep tabs on players, but unless they are never interacting with the outside world, that only accomplishes so much. What happens when a player tests positive on a Tuesday after playing the previous Sunday? My understanding of tracing and quarantining is that would then expose his teammates and recent opponents to quarantine, as well. Unless there are some alternate safe ways devised to circumvent the only steps we currently have to manage spread, I'm not sure how we can expect to get through a season without the possibility of serious disruptions, until there is a vaccine.