The Englishmen both secured top-20 finishes at the 90th US PGA Championship in Detroit on Sunday but while Rose cemented his place on the European points list, moving ahead of Oliver Wilson and Martin Kaymer as automatic picks, Casey now has to secure his berth via the world points list if he is not to rely on one of the two captain's picks.
With three qualifying weeks to go before the team is settled on August 31, with Faldo naming his picks following the Johnnie Walker Championship at Gleneagles in Scotland, Casey has committed to continuing his schedule in the United States while Rose has ditched plans to play the PGA Tour's FedEx Cup play-offs and will head back to Europe.
"I've entered the Dutch Open and Gleneagles," said Rose, following a closing one-over-par 71 at Oakland Hills that gave him a tie for ninth place, eight shots behind new champion Padraig Harrington.
"My plan was to play the FedEx Cup, but I don't know if I've earned quite enough points to be safe, so going back and play some more."
Casey, who finished in a tie for 15th following a closing 69 that left him 10 shots adrift of Harrington first heads to North Carolina to play the Wyndham Championship in Greensboro, hoping to boost his world ranking.
"I still have an opportunity to qualify, but that opportunity is now off the world points list rather than the Euros," Casey said.
"I'm a long way off that list, so I'm going to have to play, I basically have to win, simple as that.
"And all I can do, if I don't win, is play exceptional golf and you know, show the boss that I'm playing some decent stuff.
"I'm going to play FedEx Cup stuff to save going back to Europe and save playing one over there and flying back and doing too much messing around, I might as well keep playing while I'm playing fairly good golf," Casey added.