New England Patriots third-string quarterback Tim Tebow didn't play in the team's 40-9 loss to the Detroit Lions on Thursday night creating uncertainty about his chances to earn a roster spot. Lions fans chanted "Tebow! Tebow! Tebow!" with about 10 minutes left in the game and later booed when Patriots coach Bill Belichick stuck with No. 2 quarterback Ryan Mallett. Starting quarterback Tom Brady played the entire first half while Mallett stayed on for the second half. "You prepare yourself and be ready for whenever your number is called. There's nothing else to it" Tebow said after the game. Belichick didn't go into detail about why the Patriots played just two quarterbacks which leaves Tebow one final chance to lock up a roster spot -- the preseason finale Aug. 29 against the visiting New York Giants. That assumes Tebow is still with the club past Tuesday when teams must trim their rosters to 75 players. The Patriots currently have 84 players. Tebow said he would approach that cutdown day and then the Aug. 31 cutdown to 53 players just like any other day.