ST. JOSEPH, Mo. -- Kansas City Chiefs safety Dan Sorensen tore the lateral meniscus and suffered damage to the MCL in his left knee during a special-teams drill at training camp this week. Sorensen also fractured his tibia.
Sorensen had surgery at the University of Kansas Hospital and was to return on Saturday to camp at the Missouri Western State University to begin his rehab.
Sorensen will miss at least the start of the regular season.
"There is no timeframe other than we're going to examine Danny at six weeks," Chiefs athletic trainer Rick Burkholder said.
The 28-year-old Sorensen became a starter last season, his fourth with the Chiefs after being signed as an undrafted rookie from BYU. Sorensen replaced Eric Berry, who missed all but the season opener after tearing his Achilles tendon.
Berry also did not play in Thursday night's preseason opener against the Houston Texans, but he was back at practice on Saturday. Berry and Eric Murray were the first-team safeties. Murray, a fourth-round draft pick in 2016, played in 14 games for the Chiefs last season.