World number one Dustin Johnson has withdrawn from this week`s AT&T Byron Nelson PGA Tour event after suffering a flare-up of a lingering knee problem, a statement said on Monday. Johnson, who underwent surgery on his left knee in September 2019, said in a statement released through the PGA Tour he would skip this week`s event in Texas to focus on rehabilitation. The announcement comes just over a week before the second major of the season, the May 20-23 PGA Championship at Kiawah Island in South Carolina. "It is with deepest regret that I must withdraw from this week`s Byron Nelson," Johnson said in the statement. 

"Unfortunately, the knee discomfort I occasionally experience has returned and after consultation with my team and trainers, I feel it is best that I remain at home and focus on my rehabilitation work. "I am not pleased about this situation, as I was really looking forward to playing this week." The 36-year-old`s statement gave no indication of whether he would be fit for the PGA Championship, where Johnson will be aiming to capture his second major after victory in the 2020 Masters.