During his college days at LSU, Leonard Fournette was famous for trucking over defenders.

If you need an example of that, here's a clip of Fournette absolutely destroying an Ole Miss defender back in October 2016.

In the NFL, it's not as easy to run over a defender, and that's mainly because NFL players are about twice the size as most college players.

The other thing about the NFL is that no matter how big you are, you'll occasionally run into players who can truck you back. That's exactly what happened to the 225-pound Fournette during a Jaguars practice on Friday.

In the clip below, defensive tackle Sheldon Day busts through the Jaguars offensive line and then proceeds to destroy Fournette.

Ouch. Welcome to the NFL, Leonard.

Of course, if Day ever tries to brag about that hit to Fournette, the rookie running back can just bring up the time when Day couldn't even beat a tackling dummy in a one-on-one drill.

Sheldon Day recently had some trouble with a tackling dummy. Twitter

Yes, that actually happened.

If you want to see Day completely whiff on the blocking sled, there is video of it. We'd show you the video here, but there's a curse word involved. If that doesn't bother you, you can click here and check out the video.