As Mr. Mccollister stated above, "The fumble by Mariota during the Colts game did not cost the Titans the game, giving up the second onside kick in 2 games did, and missing another extra point did and not being able to contain Luck did. This is still a young team and an incomplete team where everyone needs to do better."

As the team is being rebuilt from the inside out having begun with the  OL, protection is much less the issue than many other factors. The link below verifies the Titans are currently near the top of the league in this relevant stat.

Team Quarterback Sacked Per Game: 2016 NFL Season
http://www.sportingcharts.com/nfl/stats/team-quarterback-sacked-per-game/2016/

There are a lot of moving parts to this, not the least of them being that an NFL passing pocket is only *expected* to last a matter of a few seconds with the very best of protection. Marcus must do as his coaches ask: Protect the ball AT ALL TIMES, and take off running or throw the ball away when its best.