Liverpool boss Rafa Benitez has admitted four of his top stars have received special placenta treatment to step recovery from injury.
Glen Johnson, Fabio Aurelio, Yossi Benayoun and Albert Riera have each visited a Serbian clinic in Belgrade, run by physiotherapist Mariana Kovacevic.
The unique treatment involves a massage with placenta and has recently emerged as a popular new form of speeding up the healing process for athletes with muscle problems.
All four players have since returned to full training and are in contention for Saturday's visit of Manchester City, with a Champions League trip to Debrecen on Tuesday and the Merseyside derby at Everton next Sunday.
Ironically, it was former City player Riera who suggested the treatment after hearing good reports from former teammate Pablo Zabaleta, who has underwent treatment at the same clinic in the past.
Benitez said: "We knew of other players at Premier League clubs who have been to Belgrade for treatment with this lady, and we were made aware that it was very effective. Zabaleta told Riera about it.
"She has been working for seven years with top-class sportsmen, not just footballers. So she has the experience.
"We felt it was a good opportunity to send some of our players. We sent two, Benayoun and Riera and they came back and started training straight away.
"So we decided to send two more, Johnson and Aurelio, and the same thing has happened. They have been training and all four will be in the squad against City.
"Arsenal's Robin van Persie went earlier, but now there are several more top players who are going to have treatment in the same way.
"City have sent two, (Vincent) Kompany and Zabaleta beforehand, and they were playing within days.
"There have been no injections, it is a placenta cream applied with a (massage) machine that creates waves of pressure."
He added: "Many top players have been going there for seven years, it has been successful and I believe it is safe.
"It is good for specific injuries, doctors have explained the treatment and the components of the cream that is used. We are happy with it.
"We checked it out when we became aware of the different players who had been there. I must admit we have been surprised with how well it has worked."
Benitez admits that the success of the treatment will only be fully determined on how his players come through the physical strains of a competitive match, with City proposing a real threat at Anfield.
"It means we have players available and training that we expected to be out for several weeks. Can we guarantee that they are fully fit? We will see, but they have trained with the rest of the team for three days and they are OK."