Dustin Johnson is confident his decision to join the LIV Golf Invitational Series will not hamper his chances of winning more major titles.

Johnson made a promising start to the U.S. Open with a first round of 68 at The Country Club on Thursday, but followed that up with a three-over second round of 73.

The former world number one is playing in his homeland this week for the first time since he sensationally quit the PGA Tour to join the controversial Saudi-backed breakaway circuit.

Johnson does not believe his defection from the PGA Tour, and the consequence of not playing as many tournaments against the best players in the world, will make him less of a force at majors.

Asked how sharp he thinks he will remain by playing on the LIV Tour, the American said: "Just as sharp as I would playing anywhere."

Johnson is in no doubt he made the right by call by signing up to LIV Golf.

"Yeah, obviously it was a tough decision, but I feel very confident in the decision I made," he said. "Yeah, I'm definitely happy and looking forward to obviously this weekend and the rest of the events this year."

The 37-year-old says he has not experienced any hostility from the crowds in Brookline, Massachusetts this week. 

He said: "No, fans have been great. Obviously, this is a good sports town, and a lot of people come out and support the event."

Johnson was in a share of 27th place on one over with the second round still ongoing when his compatriot Joel Dahmen moved into the lead on five under through eight holes.

Good luck #LIVGolf pic.twitter.com/4hWCHPYOmk

— LIV Golf (@LIVGolfInv) June 16, 2022