Brooks Koepka back to full fitness ahead of debut at La Quinta

Brooks Koepka makes his debut at The American Express in California

Brooks Koepka insists his injury troubles are behind him as he looks to bounce back from a disappointing 2020 at The American Express in California.

Koepka struggled for form and fitness during a disrupted 2020 campaign after undergoing knee surgery the previous autumn, with a runner-up finish at the WGC-FedEx St Jude Invitational one of only four top-10s from 17 starts worldwide.

The 30-year-old is without a win since July 2019 and played through lingering pain in his left knee and hip throughout last season, where he failed to feature in the PGA Tour's FedExCup playoffs.

Brooks Koepka finished tied-seventh at the Masters in November, having missed the US Open through injury

Koepka has had multiple stem cell therapy injections to improve his knee, with the most recent platelet rich plasma (PRP) treatment earlier this month, with the four-time major champion pleased with the results ahead of his first appearance of the year.

"I'm healthy now, so I'm not worried about it," Koepka said. "Went and actually had another round of PRP on my knee about two weeks ago, just to make sure.

"They did an ultra sound on it, they said there's barely any tear on it, so there's a lot of progress, came a long way, a lot of hard work, but just excited where it's probably the best I felt maybe since 2018.

"They take your blood, they spin it and they inject it back into the patellar tendon and there's barely - there's scar tissue there, which is good - and there's really barely any tear now, so it's a good thing."

Koepka missed the cut in his most recent appearance last month at the Mayakoba Golf Classic and is back outside the world's top 10, after beginning last year at the top of the world rankings, although feels confident that results will improve in 2021.

Brooks Koepka is one of four players from the world's top 15 featuring in California

"My whole season last year was, for the last year and a half, it's been an injury," Koepka added. "I couldn't shake it, tried to play, adjust my schedule, tried to play through it and injuries attract other injuries and that kind of sums up the season.

"I feel like I've just put it behind me, I don't really put too much emphasis on last year. My confidence is still high. I've seen so much better results, so much better in my practice sessions now that I'm healthy."

Koepka tees it up for the first two rounds - played across two courses - alongside Cameron Champ and Paul Casey, while Patrick Cantlay, Patrick Reed and Matthew Wolff are among the other names in action for the opening event of the "West Coast Swing".

World No 2 Jon Rahm withdrew from the event on Monday as a precaution due to injury but hopes to return at the Farmers Insurance Open next week, while D.J Trahan pulled out of the tournament after testing positive for coronavirus.

Watch the American Express throughout the week live on Sky Sports. Live coverage begins with Featured Groups on Thursday from 5pm via the red button, ahead of full coverage from 8pm on Sky Sports Golf.