A quick comparison at Will and the Chiefs current FB, Anthony Sherman
Will is 5 years younger, meaning he already has a leg up because in today's NFL, and especially in the backfield, youth is a huge factor on if you can make the team or not. He's one inch taller (unofficially) and nearly 15 pounds heavier. Despite being bigger than Sherman, his 40 time is nearly a quarter of a second faster (Sherman 4.75, Ratelle 4.54).
Of course, the only thing that matters at the end of the day is if you do your job better than the other guy. Will got a tough break, being behind DiMarco in Atlanta (one of the better fullbacks in the league) and injuring his ankle during training camp, but if he can outperform Sherman, there's a very good chance we'll see Ratelle playing on Sundays in 2017.