Training camp and the preseason are looked at as different properties for different players.
For seasoned veterans, it is a warmup to another season on the field
For younger players, it is an opportunity to improve and show what you can offer the team
When those two groups collide - or you have multiple players in each category - you end up with players battling for playing time. The Los Angeles Rams have several positions where this is happening.
Young Gerald has shown the ability to be an explosive downfield threat during his two seasons in the NFL, but has been unable to unseat Higbee thus far for playing time.