As the Chiefs open the preseason Friday against Arizona, all eyes will be on the ACL club -- Jamaal Charles, Eric Berry and Tony Moeaki. The Chiefs have not done any tackling in training camp, so this will be the first chance to see how the surgically-repaired knees of trio react to contact.

The coaching staff will be evaluating the backups as the starters are pretty much set. The two positions that fans will have their eyes on are NT and WR, in particular NT Dontari Poe and WR Jon Baldwin. The Chiefs' last two first-round picks have the opportunity to be impact players this season.

Questions to be answered in exhibition season:

1. Is the ACL club ready to perform? The Chiefs have been cautious with Charles, Moeaki and Berry, holding them out of several practices to make sure they don't try to speed the process too quickly. On Friday, it's time to put those knees to the test, as all three will play against the Cardinals.

"We will continue to manage those guys as well, but I think it's important for them to get reps in the game to begin to find out where they are and how they feel and how those injuries are recovering for them," coach Romeo Crennel said, via the Kansas City Star. "So we'll give them some time, and we’ll see how it goes."

2. Is Poe legit? Poe's production at Memphis last season (33 tackles and a sack) had some questioning whether he was worthy of a such a high pick. Now, Poe is backing up Anthony Toribio, who has spent most of his career on practice squads. Poe is expected to play in obvious passing downs in Kansas City's nickel defense, but everything coach Romeo Crennel has said makes it sound like Poe has some improvements to make before he displaces Toribio as the starter. 

"He needs to work on technique, he needs to work on understanding the system, he needs to get the calls correct all the time," Crennel told the Kansas City Star. He's got a ways to go."

3. Is Baldwin ready to be No. 1? Dwayne Bowe is holding out and Baldwin will get his first chance as Matt Cassel's go-to receiver. Bowe figures to eventually join the team -- he has nothing to gain by holding out. If anyone can benefit from Bowe's holdout, it is Baldwin. The second-year receiver has been impressive during training camp and is looking to prove himself after an injury-shortened rookie season when he put up 21 receptions for 254 yards and a touchdown.

Follow Chiefs reporter C.J. Moore on Twitter @CBSSportsNFLKC and @cjmoore4.