These two players replace CB Buddy Jackson, who was released yesterday, and OL Colin Kelly, who has an injured knee. Kelly was signed as an undrafted free agent in May.
Don't too much into these signings. I'd consider these additions to be camp bodies/replacements at best. KCChiefs.com has more info on both players:
Tepper (6-6, 354) has played in six games (four starts) in one NFL season with the Indianapolis Colts (2011). In 2011 and 2012, Tepper split time between the Colts practice squad and active roster before being released on Aug. 31, 2012. He originally entered the NFL as an undrafted free agent with the Dallas Cowboys in 2010. He was released by Dallas before the start of the 2010 season. Tepper played collegiately at California and prepped at Pacifica High School in Garden Grove, Calif.
McIlwain (5-10, 194) originally entered the NFL as an undrafted free agent with the Atlanta Falcons in 2011. After being released by the Falcons before the start of the regular season, he spent his rookie year on the New Orleans Saints practice squad. McIlwain was released by the Saints on Aug. 27, 2012 and then signed on with the Carolina Panthers where he served on their practice squad roster for the season. McIlwain was an All-South Atlantic Conference player at Newberry College.