Leishman became the first Australian to win on the US PGA tour this season at last weekend's Travelers Championship, moving him to the top of a British Open qualification list.
The top two players not previously eligible from a cumulative money list, taken from The Players Championship through to the Greenbrier Classic, will gain entry into the 2012 Open at Royal Lytham & St Annes on July 19-22.
But even if Leishman remains in the top two, his major championship dreams look set to be put on hold because he is in the midst of a green card application in the US.
Leishman is eligible for a green card (permanent residency) due to his marriage to wife Audrey, who is an American citizen.
However, the process is lengthy, taking usually a minimum six months and, under US immigration law, someone with a pending application for permanent residency is unable to leave the country without prior consent.
Receiving advanced parole can take around two months and, while Leishman has made an eleventh hour bid, he still must sweat out the process.
His other hope is for his green card to be processed in time, a small chance given his application was lodged five months ago.
"I definitely don't want to miss the British so hopefully it will all come through in time but we haven't even had our interview yet so I'm not sure it's going to happen," Leishman said.
"The British is probably my favourite golf tournament of the year. I love playing links golf and I love everything about the UK so it would be good to go over and have a crack at it.
"It wasn't looking real good but my lawyers have just confirmed advanced parole has been lodged ... so fingers crossed it arrives before the British and, if I qualify, I can go."
In the meantime, Leishman will take his form to the AT & T National at Congressional Country Club just outside Washington DC.
Jason Day, Adam Scott, Greg Chalmers, Robert Allenby, Nick O'Hern and Rod Pampling join Leishman in an attempt to keep the Aussie success rolling.
"It would be awesome if we opened the floodgates for all of the Aussies and more for me as well," Leishman said.
"It's funny because this week probably sets up better for me than last week although it will be tough to back up from a win.
"But in saying that, there is no reason I can't play well again. I'm hitting it well and I felt good over the ball so I'll be doing my all to keep the roll going."
Day has decided to play, despite the impending birth of his first child, given his confidence on the layout.
The 24-year-old was second to Rory McIlroy in the 2011 US Open and famously closed the tournament with 45 straight bogey-free holes.
Elsewhere, Greg Norman will return to competitive golf by playing the third major of the Champions Tour, the Senior Players Championship.
Norman will join Peter Senior in Australia's quest for a first major of any kind over the past six years.