It's usually guys in HiA and lower that need the rest at the all Star break due to their low durability. I can usually get a guy who is at 97 or 98, back to 100.
At the major league level, you should definitely be employing an active rest strategy to avoid any late season durability issues that could lead to your best players not playing in late season division games. Manager settings to get your starters out of the game when there is a 5+ run lead tends to work well throughout the season. Also, taking low durability guys (less than 85) out of the starting lineup when you play a bottom of the league team helps as well. Some of these management strategies are certainly a lot of work, but if you are only running one team, it should not be that cumbersome.