Titans QB Ryan Tannehill carted off after Khalil Mack's tackle injures his leg

The Tennessee Titans were already in a slump, having lost three in a row. Then in the first quarter Sunday, their quarterback was being taken off on a cart.

On a run against the Los Angeles Chargers, quarterback Ryan Tannehill had his right foot and ankle pinned underneath Chargers linebacker Khalil Mack on a tackle attempt. He was carted off the field with an injury.

The Titans will hope for the best, though the injury looked bad. Rookie Malik Willis took over for Tannehill.

Willis is an exciting player but he didn't look ready when the Titans had to start him twice earlier this season. With Tannehill injured, Willis had 135 passing yards total in his two starts. Willis could develop into a fun player but the entire offense changes with him at quarterback.

The Titans were once 7-3 and in control of the AFC South. They're still in good shape in the division, but the Jacksonville Jaguars' upset win in overtime over the Dallas Cowboys improved their record to 6-8. If Tannehill misses time, Willis will have to keep the offense going and come up with some wins. Jacksonville is coming on strong, and the Titans suddenly have a lot of issues to deal with.