Liverpool manager Brendan Rodgers says they hope to sort Daniel Sturridge's "underlying issues" with injury after sending him to the United States again.
The 25-year-old, who has played 18 times this season, has flown out to a specialist to fix his hip injury.
He also spent a month in the US in December to deal with a thigh problem.
Rodgers said: "The medical team here, liaising with medics in America, are doing everything we can to give Daniel every opportunity to stay fit."
He added: "If you look at his career, he's had little issues along the way.
"I think we have found some underlying issues that maybe relate to Daniel's problems this season and the ongoing ones he's had."
Rodgers was asked if some of the England striker's problems could be mental rather than physical.
"I'm not sure. Daniel is like every other player - he wants to play and be available," Rodgers added. "We have to do everything we can to get him on the training field and into the game, hence the reason for looking into the issue."
The 25-year-old England international is visiting Dr Peter Asnis, an orthopaedic surgeon based in Boston.
Meanwhile, captain Steven Gerrard, who has four games left before he leaves for US Major League Soccer team LA Galaxy, is expected to face QPR on Saturday, having been left out of the squad for Tuesday's loss to Hull.
"The Saturday-Tuesday games were always going to be difficult for him," Rodgers said. "But he's had a good week of preparation and he'll be fit and firing for the weekend."
And the Liverpool boss confirmed full-back Jon Flanagan will miss a large part of next season after knee surgery. The 22-year-old England international has not played this season.
"He's been a huge miss for us," Rodgers said. "Second half of last season he was arguably the best full-back in the league.
"He fought back, trained and looked brilliant - but for him and his career he definitely needed the operation. Six to nine months, then get him back fit and stronger than ever."