Eric DeckerOn Sunday, the Denver Broncos will play the preseason game that "matters" against the San Francisco 49ers.

Denver has shown some good things and some bad things in the preseason.

At times the offense has moved down the field but other times it has really stalled.

The defense has put some great pressure on the opposing quarterbacks but have gotten gashed in the running game.

The third preseason will be the final tune-up for the starters and there is still a lot to prove. Here are four things the team needs to accomplish before the regular season.

Manning throws a TD pass

New quarterback Peyton Manning has shown that he is healthy. Some of his passes have fluttered and seemed wobbly but his arm strength is getting better. He has moved the team on several occasions down into the red zone but the drives have not resulted in touchdowns.

Manning's three interceptions and zero touchdown passes shouldn't be worrisome because it is preseason. Manning needs to throw a touchdown pass for himself. For the veteran quarterback to feel completely comfortable with his new team he needs to do what he is known for doing.

If he throws a touchdown against the 49ers despite the AFC West juggernaut being one of the toughest defenses in the league, it will make Manning and the team feel ready for the regular season.

Get Thomas involved

Has Demaryius Thomas been on the field this preseason? He has three catches in the two games and has not produced a big play. Is Manning not connected with the big-play receiver? It seems that way.

Manning has been throwing to Eric Decker, Jacob Tamme and Brandon Stokley a lot this preseason. He has played with two of those players and the third (Decker) developed a quick relationship with the future Hall-of-Fame quarterback.

Thomas needs to be factor in the game against the 49ers. A long completion will go a long way to quieting the critics.

Someone make a tackle

The Broncos are thin at linebacker and have a lot of youth, besides Mike Adams at safety. There has been poor tackling from these positions especially in the loss to the Seahawks.

Middle linebacker Joe Mays, who is a great leader, missed a couple chances to bring down Seattle running backs for losses or short gains. Starting safety Rahim Moore also missed some tackles. Moore, who was given the starting job in camp, needs to so he is ready to play in the NFL.

As a whole the defense needs to tackle better. Stopping the run has always been a problem for the Broncos. The 49ers have a great running game and will be a tough test for Denver. Become a better tackling team and the defense will be on the way up

Wolfe or Ayers?

Robert Ayers, who has been a starter the last couple years, lost his job to Jason Hunter in training camp. Hunter tore his triceps and will be lost for the season. Rookie Derek Wolfe jumped into the spot and started against the Seahawks. Wolfe has made plays and looks ready to take over the job.

Ayers has also looked good against the opponent's second-team. The former first round pick seems motivated and wants his job back. Who will Jack Del Rio pick to be his starting defensive end opposite of Elvis Dumervil?

Wolfe looks to be the favorite going into Sunday's game. He has shown ability to get the quarterback and to make plays. Ayers could still make a push but at the moment it looks like the rookie's job to lose.