What to watch: Dolphins-Jaguars

The Miami Dolphins will play their second preseason game in five days when they travel to face the Jacksonville Jaguars Friday at 7:30 p.m. ET. Miami lost to the Dallas Cowboys, 24-20, in the Hall of Fame Game last Sunday.

Here are three things to watch in Friday’s exhibition game for Miami:

1. Offensive-line play: The big men up front have been Miami’s most-maligned unit since the start of training camp. The Dolphins still have more questions than answers on their offensive line entering their second preseason game. Left tackle Jonathan Martin, who is one of the keys to the season, played mostly above the line in limited snaps against the Dallas Cowboys. Martin must develop consistency and it starts in the preseason. Other players like right guard Josh Samuda and backups like Dallas Thomas and Nate Garner must also prove to the coaching staff that they can provide depth, as well.

2. Quarterback Ryan Tannehill: Miami’s starting quarterback had an underwhelming performance in the preseason opener. Tannehill was 2-of-5 passing for 11 yards. Despite a small sample size, Tannehill missed a couple of throws and wasn’t accurate. He was also credited for a fumble during a botched hand off with running back Lamar Miller, although Miller probably deserved blame. Tannehill will get more playing time this week and needs to get in rhythm. He will have starting receiver Brian Hartline this week and possibly Mike Wallace, so there shouldn’t be any excuses. Tannehill has been up and down in training camp, including five combined interceptions in practice on Tuesday and Wednesday.

3. Miami’s tackling: The Dolphins’ coaching staff did not go overboard this week after the team’s poor tackling display against Dallas. It is not the first time a team struggled with fundamentals in the first exhibition of the year. However, Miami’s defense on all levels -- starters and backups -- must tackle better Friday night against Jacksonville or this will be considered a trend. The Dolphins must do much better against the run after allowing 170 rushing yards and 5.0 yards per carry against the Cowboys. Miami’s run defense is usually disciplined and needs to begin rounding back into form.