Golf-Koepka finishes 47th at Bay Hill, vows to keep grinding

March 8 (Reuters) - A day after shooting the worst score of his PGA Tour career, Brooks Koepka went 10 shots better with a one-under-par 71 in the final round at the Arnold Palmer Invitational in Florida on Sunday.

Not that the American was particularly impressed.

His long game was still bad, Koepka said, using an expletive to describe it, though he at least was happy with his putting.

"Found something with my putting, so my putting, the touch is back. I feel very confident with that," the world number three said after finishing equal 47th, 13 strokes behind English winner Tyrrell Hatton at Bay Hill in Orlando.

"I just need to figure out the long game ... Still close on the swing, sometimes it's there and then sometimes it's not."

Koepka's form this year has been a far cry from the dominant player who won back-to-back U.S. Opens (2017-18) and PGA Championships (2018-2019) not so long ago, becoming a clear world number one in the process.

He quickly played his way back into form from a wrist injury that kept him out for three months early in 2018, but a partially torn left knee patella tendon last year has proven more problematic.

After having stem-cell treatment, he reinjured the knee slipping on concrete in South Korea in October and missed three months recuperating.

Koepka on Sunday vowed to keep working until he found the old spark, though with the Players Championship starting on Thursday, and the Masters looming early next month, it is hardly the ideal time of year to be searching for one's game.

"Eventually all the hard work's going to pay off," Koepka said.

"It's just a matter of how quick it's going to turn. Listen, it's coming together piece by piece." (Reporting by Andrew Both in Cary, North Carolina; Editing by Stephen Coates)