According to ESPN’s Mike Reiss, “Those close to the situation believe that time is on their side, and if Gronkowski continues to make progress, he has a good chance to be active for Super Bowl LII.”
Reiss also notes that Gronkowski has been at Gillette Stadium all week, which is another good sign for his recovery.
Everyone responds differently to concussions, but the majority are treated as a one-week injury in the NFL, where a player misses the next week before returning to the field. This timeline suggests that Gronkowski might not have played if the Super Bowl were on January 28th, but he should be ready to take the field since there’s a bye week before the big game on February 4th.
Gronkowski has had pretty terrible luck for the postseason. He suffered an ankle injury in the 2011-12 AFC Championship Game that limited his value in the Super Bowl; he re-broke his arm in the divisional round of the 2012-13 postseason; he tore his ACL in the 2013 regular season and was unavailable for the playoffs; he was healthy in both 2014 and 2015 (he did suffer a knee injury against the Broncos in the regular season that limited him); he suffered a back injury that ended his 2016 regular season; and now he was concussed in the 2017-18 AFC Championship Game.
Hopefully Gronkowski will be healthy enough to play in the Super Bowl and will be his normal, game-changing self.