I'm not so sure. Part of the equation as to when he plays is also getting a brand new group of O-linemen (Jackson, Hunt, Kindley from the Draft - Karras, Flowers - free agents - Davis, Deiter and another "Joe Schmo" from last season) to come together and gel as a unit and this is more difficult by the Covid-19 virus social isolation.
I may be totally wrong, but I still think that we are rolling with Fitz in 2020 and "the Beard" continues to pull the team together and he also takes the hits while the O-line becomes fully functional. Tua's job this year is to learn to be a professional from Fitz, learn how to read NFL Defenses, learn how Fitz inspires teammates through his tough gritty play, learn how to win the respect of all teammates, learn, learn, learn, learn while his body recovers 100%... Furthermore, I have zero problem in playing Rosen, if Fitz gets injured or craps the bed. Josh is the Dolphins low cost insurance.
Besides, Aaron Rodgers waited 3 years on the bench behind Favre. Tony Romo waited 2 years with a clipboard before he got his shot. Tom Brady, Drew Brees and Pat Mahomes all spent a year on the bench watching and learning before getting their respective opportunities to start. I believe in Tua, but we don't have to rush. Patience, in this case, is a virtue.