I read it as he will be ready before SEC play, but why risk it. At least I hope that's how I should read it.
That wouldn't be an unreasonable interpretation, but I feel like surely these announcements are vetted, and there are pretty clear ways to communicate that. "Return before SEC action" and "Return by the start of SEC action" are both clear timelines. "Expected to return around the start of SEC play" is pretty clear and leaves open the option that it won't be the first game. "Will be back early in SEC play" is reasonably clear although "early" could be 2 games in or arguably as late as the end of the first third of the SEC season.
"Expected to return during SEC play" could mean he's expected for game one. Or it could mean he's expected sometime around the middle of the SEC schedule. Or it could mean they don't really have confidence in a timeline yet, but they feel like he'll make it sometime during the season, maybe early in the SEC schedule, maybe late in the SEC schedule.
Maybe it's expecting too much competence from our athletic department, but surely if they wanted to communicate that he would be back at the beginning of SEC play, they could figure out how to do that and wouldn't instead use a phrase that could mean he will be back the last week of SEC regular season play? Just doesn't seem like there is anything to gain from using that phrasing if they actually think he'll be back early in SEC play.