Former world number one Brooks Koepka has withdrawn from the AT&T Byron Nelson just eight days prior to the start of the PGA Championship, potentially leaving the two-time champion's participation at the year's second Major in doubt. 

Koepka has been replaced by Japan's Satoshi Kodaira in Texas, with the PGA Tour not revealing the reason for the four-time Major winner's absence, which was announced on Wednesday.

However, the 32-year-old has endured a number of injury setbacks over recent seasons and has not featured since missing the cut at the Masters in April.

The American underwent surgery on his right knee in March 2021, returning to feature at that year's edition of the Masters within a month of the operation.

Koepka's participation at the PGA Championship, which he won in both 2018 and 2019 to become the first player to successfully defend the title since Tiger Woods in 2007, now looks to be in doubt with just over a week to go until tee-off in Oklahoma.

The 32-year-old has experienced a frustrating season to date, missing the cut in six of his 13 tour starts to sit 67th in the FedEx Cup standings. 

Brooks Koepka WD from the AT&T Byron Nelson and is replaced in the field by Satoshi Kodaira.

— PGA TOUR Communications (@PGATOURComms) May 11, 2022