Posted by Sabrina B. @gametimegirl There are three covers for this week’s Sept. 19, 2011, issue of Sports Illustrated, on newsstands tomorrow. The national cover features Jets quarterback Mark Sanchez. It is Sanchez’s third appearance with the Jets — he previously appeared on the Jan. 26 and Sept. 6, 2010 covers — and his fourth overall. (He appeared on a regional cover of the 2008 College Football Preview [dated Aug. 15, 2008] while at USC.) Check it out after the jump…