Golfman25,
It is truly a fine line as you stated but things have a way of working themselves out. At least twice in his baseball journey, my son has told me that he wanted to quit or slow down on baseball for a while. Once when he was eight, he told me he didn't want to play Little League baseball that year, but luckily his little brother was so excited to sign up for his first season that it rekindled my older son's interest and by signup day he decided he would play after all.
Later when he was 15 he went through a little burnout period but after a few weeks of taking time off after an unenjoyable high school freshman year in a program in which baseball was definitly #4 on the school's sports totem pole and the JV coaches were guys who admitted they only knew football and nothing about baseball and hadn't even played in high school, we rekindled his passion by joining a new travel team that was more of a challenge and backed off the extra work at home until HE decided he wanted to do some.
It will all play itself out if you try your darndest to make the game fun again by maybe backing off a little especially as he's trying to also focus on basketball. The story has turned out great for my son going into his senior season in college and I'm sure it can turn out that way for yall also.