Dustin Johnson was seen warming up on the range but not moving freely
Johnson arrived in Augusta last week as world No 1 and favourite to win his first Masters title.
However, his odds of victory drifted after it emerged that he had fallen while playing with his son Tatum and damaged his back.
But now The Sun claim Johnson's trainer has confirmed that he will attempt to play despite suffering pain in his lower left back below the rib-cage.
"He told us [last night], 'I'm going to do everything I can to go out and play tomorrow,'" trainer Joey Diovisalvi said.
And Johnson was reportedly seen taking painkillers during his warm-up to help with the pain.
The American is due to tee off at 7.03pm UK time with fellow countrymen Jimmy Walker and Bubba Watson.