We're firmly into the training camp portion of the 2017 NFL season now, which means we're going to start seeing players progress, regress, and unfortunately, get injured. Down in Miami, we've already got a pretty important one. 

Dolphins running back Jay Ajayi "got his bell rung" in practice on Monday, and according to Armando Salguero of the Miami Herald, he's being evaluated for a concussion. 

Ajayi emerged last season as the foundation of the Dolphins' offense, taking over as the starter a few games into the year. He ended up running for 1,272 yards and eight touchdowns, averaging 4.9 yards per carry along the way. He rushed for over 200 yards in back-to-back games, becoming the fourth player ever to do so, and eventually made the Pro Bowl as well. 

His backup, Kenyan Drake, is confident the team's other running backs can step up and fill in for him if necessary. But he did say that he thinks Ajayi will be back soon.  

The Dolphins losing Ajayi for any length of time would be a huge blow to their hopes this season, so hopefully Ajayi can progress in and out of the concussion protocol quickly.