MIAMI GARDENS, Fla. (AP) — With first-team quarterback David Garrard out for up to a month, Dolphins quarterback of the future Ryan Tannehill had a promising preseason debut Friday night.

Tannehill completed 14-of-21 passes for 167 yards, including an 11-yard touchdown to tight end Charles Clay in the third quarter for Miami’s only score in a 20-7 loss to the Tampa Bay Buccaneers.

Garrard was scheduled to start after being listed first on the depth chart, but his agent confirmed Friday he’s slated to have knee surgery. His absence is likely to knock him out of the three-way battle for the starting quarterback job he was waging with Tannehill and Hart High graduate Matt Moore, who started the last 12 games last season for Miami.

Dolphins starting linebacker Kevin Burnett also missed the game despite taking part in warm-ups. Backup offensive lineman Nate Garner was helped off the field in the fourth quarter after sustaining an ankle injury.

Tannehill, taken eighth overall in the 2012 draft, is the Dolphins’ quarterback of the future, but he’s hoping to convince his coaches to make him a starter right away.

He made a pretty argument for his case on Friday night.

Before his TD pass, a strike down the middle, Tannehill had a touchdown pass to wide receiver Roberto Wallace late in the second quarter overturned by instant replay. Two plays later, Tannehill missed Clay near the sideline on a fourth-and-goal from the 3-yard line.