Leftwich was only 2-of-6 for 12 yards in three series against Tampa Bay's first-team defense. David Garrard was 11-of-14 for 129 yards for the Jaguars.
Tampa Bay starting quarterback Jeff Garcia hit 6-of-6 for 43 yards and a touchdown, but was sacked once and fumbled a snap in three series.
Luke McCown replaced him and went 9-of-13 for 66 yards.
The Jaguars scored 24 points in the second quarter.