Both players were in the Pro Bowl last season.
Houston is in the final year of a contract he signed as a third-round draft pick in 2011. With 26.5 sacks and two Pro Bowl appearances in his three NFL seasons, Houston has outperformed that contract. He is to make a base salary of $1,406,000 this season.
The Chiefs drafted an outside linebacker, Auburn's Dee Ford, in the first round this year.
Though he made the Pro Bowl, Flowers is coming off one of his worst NFL seasons. Pro Football Focus gave him a rating of minus-5.9, by far the lowest for Flowers since his rookie season in 2008.
The Chiefs under general manager John Dorsey and coach Andy Reid have expressed a preference for cornerbacks who are bigger and more physical than the 5-foot-9 Flowers. The other starting cornerback is 6-3 Sean Smith. Marcus Cooper at 6-2 was the third cornerback last season. This year the Chiefs drafted 6-0 Phillip Gaines of Rice in the third round.
Flowers is to make a base salary of $5.25 million and have a salary-cap figure of $10.5 million this season.