This is harsh, but probably correct.
It is a truism that the most popular guy on campus is always the 2nd string QB. Nevertheless, assuming it is true that Ty is injured, Coach should have had the courage to tell Ty, "You are hurt and not playing well enough to win. I owe the rest of the team a chance to win this game. Matt will start the second half." That would have been leadership.
It would not mean Ty is a failure. It just means he is hurt. It would not mean the program is giving up on Ty. But the team matters more than one individual. Or it should.
In
Star Trek: The Next Generation, Counsellor Troi keeps taking the test to become an officer with command authority, and keeps failing the test. She only passes the test when she shows that, if the situation requires, she will knowingly order one of the crew members to his death in order to save the ship and the rest of the crew. That is the hard truth about leadership. Coach DeBoer would do well to ponder this lesson.