QB's ability to move the chains with his feet was vital component of 2016 offense

Marcus Mariota’s mobility will an important issue as the Tennessee Titans look to next season.

There is little — if any — concern that Mariota will step back into his role as starting quarterback. The issue is whether the broken right leg that required him to miss the final game of the regular season and to undergo surgery will cause him to lose a step.

That’s because the 2015 Heisman Trophy winner has shown that he is not just a capable runner in the NFL. He also is an effective one.

And he was only getting better.

In his 15 appearances during the 2016 season, Mariota produced 19 rushing first downs on his 60 attempts. In 12 starts as a rookie, he had just 12 first downs rushing and moved the chains 29.4 percent of the time.

Among the franchise’s starting quarterbacks in the Titans era (1999-present), only Steve McNair and Vince Young recorded first downs more often with their feet.

A rundown of the most rushing first downs by a Tennessee Titans quarterback in a single season (1999-2016):

Steve McNair, 1999 – 34 (72 rushes, 47.2 percent)

Steve McNair, 2001 – 31 (75 rushes, 41.3 percent)

Vince Young, 2006 – 31 (83 rushes, 37.3 percent)

Steve McNair, 2002 – 29 (82 rushes, 35.4 percent)

Vince Young, 2007 – 24 (93 rushes, 25.8 percent)

Steve McNair, 2000 – 23 (72 rushes, 31.9 percent)

Vince Young, 2009 – 20 (55 rushes, 36.4 percent)

Marcus Mariota, 2016 – 19 (60 rushes, 31.7 percent)

Ryan Fitzpatrick, 2013 – 15 (43 rushes, 34.9 percent)

Often, their best years in that regard were among the team’s best seasons of recent memory. In fact, the Titans never have finished worse than 7-9 when starting quarterback had at least 20 rushing first downs — and the only time that happened was 2001 (7-9).

McNair’s peak of 34 rushing first downs came in 1999, the year Tennessee reached the Super Bowl. He had 29 in 2002, when the team advanced to the AFC Championship.

The only time Young took the Titans to the postseason was 2007, when he had 24 rushing first downs.

Mariota’s percentage of first downs on runs might have been higher, but coaches put in more designed runs this season to take advantage of his particular skills. Some of those were called on first down and were designed to create favorable down-and-distance scenarios for the plays that followed.

The Titans don’t just need him to run. They want him to run.

Mariota will have to show he can still do so on a leg that needed to be put back together.