You don't have to start him for his boosts to still work. As long as he's in your lineup he does not have to be on the field. My line is Terror, Bruce Matthews, Grimm (he's actually a GREAT center), Yanda, and UL Willie Anderson. Tornado is my backup C.
To keep Legends chem at 40+ I run UL Zimmerman as backup LT, Haley's 95 OOP at backup LG, Gregg at backup RG, and Blount's 95 OOP as backup RT