World No. 1 Dustin Johnson won’t compete in this week’s Valero Texas Open, the PGA announced Monday. No official reason was given for Johnson’s withdrawal. Just six hours earlier, Valero Texas Open organizers had announced Johnson had committed to play in the event in San Antonio. Johnson reportedly agreed to play prior to Friday’s deadline. Ryan Brehm will replace Johnson in the field. The Valero Texas Open is a tune-up event for the Masters. Johnson won at Augusta last year to be fitted with his first green jacket. Johnson was named PGA Player of the Year last season, the second time in which he has won the honor. The Valero Texas Open runs Thursday through Sunday. --Field Level Media