Running back DeMarco Murray (knee) and Quinton Spain (back) also missed practice as the Titans began preparations for Saturday's visit to the top-seeded New England Patriots in the AFC divisional round.
Ryan missed practice because of an ankle injury, and his absence was noteworthy for reasons beyond his health issue -- he spent the previous four seasons with the Patriots before joining Tennessee as a free agent in March 2017.
While New England head coach Bill Belichick said Ryan's background with the Patriots would not be a factor, his Tennessee counterpart took a different viewpoint.
"Oh, we interrogated him until he was ready to drop yesterday," Titans coach Mike Mularkey said on a media conference call. "No, it wasn't quite that serious. But, we had a cup of coffee together, I'll say that."
Ryan had 13 interceptions in his four seasons with New England, but did not pick off a pass with Tennessee. One of his former teammates also was unconcerned about any inside information he could provide the Titans.
"Logan probably can't help them much. I know that much," Patriots safely Devin McCourty said jokingly.
McCourty and Ryan are friends, having played in the same secondary. Both players also are products of Rutgers, although McCourty was three years ahead of Ryan.
"The guy, he's a brother to a lot of us in there, a real good friend of mine, but there's nothing I want more than to see him lose Saturday night," said McCourty. "So, as close as we are, that's not going to change, and he's going to compete and be the same way. It will be fun to talk a little trash to each other."