World number one Tiger Woods said he was merely erring on the side of caution when he decided to play just nine holes during Wednesday's ProAm.

Woods, who is bidding for his first Barclays title this week, said there were some concerns about his back at the start of the day.

However, he is confident that pain can be overcome if and when he changes the bed at the New Jersey hotel he is currently using for this tournament.

"It was stiff this morning after a soft bed," Woods told journalists on Wednesday.

"Just one of those things, sleeping in hotels and I didn't want to push it, so just took it easy," added Woods, who is the number one player on the FedEx Cup standings.

Golf 365