ST. JOSEPH, Mo. -- The Kansas City Chiefs open 2022 training camp Wednesday at Missouri Western State University. Here's a closer look at a few storylines:

The player with the most to prove: Nobody is suggesting gloom and doom for quarterback Patrick Mahomes, but there's no denying his football world has changed since the Chiefs ended their 2021 season with a loss to the Cincinnati Bengals in the AFC Championship Game. The Chiefs traded his top wide receiver, Tyreek Hill, and lost two of their other top pass-catchers from recent seasons, Byron Pringle and Demarcus Robinson, to free agency. Mahomes will throw to a new cast of players without a clear candidate to replace Hill as the go-to wide receiving target. Throw in Mahomes' dismal second half and overtime against Cincinnati and he's under more pressure than normal for an established starting quarterback, even one with his considerable accomplishments.

Fiercest fantasy-relevant battle: Free agent additions Marquez Valdes-Scantling and JuJu Smith-Schuster and rookie Skyy Moore join the returning Mecole Hardman to form the main group of wide receivers. But the Chiefs still have to sort out who's going to replace Hill as the No. 1 receiver and which other wideouts make the biggest statistical contributions. Hardman, as the only one who played with Mahomes before this season, would seem to have an advantage but his contributions in three seasons with the Chiefs have been inconsistent. Smith-Schuster is the most accomplished of the bunch, but his only 1,000-plus-yard season was back in 2018. Mahomes had a good thing going with Valdes-Scantling during offseason practice, but there's no guarantee that continues during camp or when the regular season begins.

Most impactful offseason addition: The Chiefs have no shortage of candidates in this category, including Smith-Schuster, Valdes-Scantling and Moore, rookie cornerback Trent McDuffie and veteran safety Justin Reid. But the new player they most need to play well is defensive end George Karlaftis, the second of the Chiefs' two first-round draft picks. The Chiefs' pass rush, which slumped to 29th last season in sacks, is desperate for a refresh, and they're most likely to get help from Karlaftis. Chris Jones and Frank Clark again should lead the pass rush for the Chiefs, but that tandem proved incapable of providing adequate pressure on opposing quarterbacks last season. Karlaftis needs to be a factor right away.

Training camp is a success if: The defense comes together before the start of the regular season. The Chiefs parted ways with several longtime defensive regulars, most notably safety Tyrann Mathieu. They have a lot of new pieces and many, including first-round draft picks in McDuffie and Karlaftis, will have to play major roles right from the start. The Chiefs have so much to pull together in a limited time that defensive coordinator Steve Spagnuolo suggested during the offseason they would be racing the clock this summer to make sure everything is ready by the Sept. 11 opener. Spagnuolo can be difficult on rookies, making them repeatedly prove they can handle their responsibilities before he's comfortable giving them significant playing time. He may have to compromise his standards this season in the cases of McDuffie, Karlaftis and perhaps others.

Camp prediction: McDuffie will leave training camp as the Chiefs' emerging star in the secondary. The Chiefs asked a lot of McDuffie in offseason practice as he worked at both outside cornerback and in slot coverage. He handled it all well, leaving the Chiefs encouraged that he could have a big rookie season. McDuffie looked more like a veteran as he was rarely caught out of position. The Chiefs need a big season from McDuffie after losing long-time starter Charvarius Ward in free agency. Another strong candidate for playing time at cornerback, Rashad Fenton, missed all of offseason practice while rehabbing from a shoulder procedure.