The Japan international completed his move to Merseyside on Friday, but despite being registered in time with the Premier League, Liverpool faced a wait on whether Wataru’s work permit would arrive in time.
But the club have now confirmed Endo has received clearance and will be part of the matchday squad.
It remains to be seen whether the 30-year-old will start against Bournemouth, with team news to be confirmed at 2pm, but he is expected to be named on the bench.
Liverpool are expected to be further boosted by the return to the squad of Stefan Bajcetic.
Speaking on Endo’s switch from Stuttgart on Friday, Klopp insisted there would “not be a physical problem” with throwing him straight in.
“He’s in a good shape,” the manager said.
“Of course we need to figure out how quick can we put him in, but it will not be a physical problem, let me say it like that.
“And the rest, he should play here the position he played for Stuttgart, so there’s not a massive difference.
“Yes, of course, we do things slightly differently but in the end it would be cool if he could win challenges and pass the ball from A to B.”
Liverpool paid around £16 million to sign Endo, following the arrivals of Mac Allister and Dominik Szoboszlai earlier in the summer.