Anthony Kim and David Toms have confirmed they will not play in the Open Championship at St Andrews, starting on Thursday week.
Kim, the world number 11, underwent surgery on a thumb injury after finishing third in the Masters at the end of April, and was expected to miss most of the summer.
His top priority is to regain fitness for the Ryder Cup as he still lies third in the US points standings.
He was a star of their victory two years ago, thrashing Sergio Garcia in the top singles match.
Former US PGA champion David Toms has been carrying a shoulder injury for most of the season and although he has been playing well recently, the veteran has opted to remain at home.
The pair's absence allows fellow Americans Ricky Barnes and Davis Love III to take their place in the line-up, at 64th and 68th being the highest non-exempt players in the world rankings.
Love's reprieve means the 46-year-old will extend a run of playing every Open Championship since his debut in 1987.
His best finishes were fourth at Sandwich in 2003 and fifth at Royal Troon the following year, while the 1997 US PGA winner was sixth in the US Open at Pebble Beach only three weeks ago.
First reserve now is Australian Jason Day and if two more players drop out England's Brian Davis, twice a runner-up in America this season, will receive a call-up.
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