Tiger Woods says it is still too soon to know if he will be able to take his place in the field at the Masters in two weeks' time.

The world number one had to withdraw from last week's Arnold Palmer Invitational at Bay Hill because of a recurring back injury that has severely hampered him this season.

Woods, who has not missed the trip to Augusta since 1994, has admitted that he is finding it "very frustrating" as he attempts to get to the root of his latest injury set-back.