The San Francisco 49ers are set to take on the Denver Broncos in the first football game at Levi's Stadium on Sunday. Here are five things to watch for:

1) Middle of the defensive line - Mike Purcell started against the Baltimore Ravens and looked like an undrafted free agent who had spent the previous season on the practice squad. He was pushed around throughout the game as the Ravens ran for over 200 yards.

Fortunately for the 49ers, Ian Williams was activated from the Physically Unable to Perform list last week. Williams earned the starting nose tackle role in training camp a year ago and should improve the middle of the 49ers defensive line.

The impact of either on the game may be limited a bit by the Broncos style of offense. The Broncos often employ three wide receivers which would put the 49ers nickle defense on the field and take the nose tackle off. That's not necessarily a bad thing as it would bring Quinton Dial and Tank Carradine onto the field and give us another look at the two young pass rushers.

2) Slot corner - What better way to find out how good your slot corner is than putting him out there against Peyton Manning and the wide open Broncos offense. Look for Jimmie Ward to be on the field early and often tomorrow. Ward struggled a bit against Baltimore and finds himself with a bigger challenge this week trying to cover veteran Wes Welker. This could be a good preview of what's to come early in 2014.

3) Adam Snyder and Ryan Seymour - These two appear to be locked in a battle for the eigth and final spot on the 49ers offensive line. Both are versatile, Snyder can play all five positions while Seymour can go between guard and tackle. Snyder may have an advantage because he has more time in the 49ers system, but Seymour is making a strong push to make the roster. The Broncos defensive front is quite physical and should provide a good challenge for both.

4) Inside linebacker - Chris Borland and Michael Wilhoite are fighting to fill the spot left open next to Patrick Willis with the injury to Navorro Bowman. Both struggled in pass coverage last week against the Ravens, and like Ward will face an even greater test in coverage on Sunday. Borland has shown a tendency to fly around the field which has led to finding himself out of position at times. This is something that he will look to improve on this week.

5) Backup Quarterback - Blaine Gabbert finished the Ravens game 3-11 for 20 yards and one interception, not good, but he also had three of his passes dropped. Based on reports from practice this week it does not sound like he has performed well. This may be a good thing actually. So far throughout his career Gabbert has been known as a practice star who fizzled once the bright lights of the game came on. Perhaps he can flip the script this week.

Be sure to follow the game tomorrow on 49erswebzone tomorrow as Jack will be providing a live blog with information and analysis from The Tool Shed starting at 12:45.