Liverpool boss Jurgen Klopp says Daniel Sturridge must learn "what is serious pain and what is only pain" in order to overcome his injury problems.
The 26-year-old striker withdrew shortly before the Reds' Europa League win over Bordeaux on Thursday after picking up a foot problem in training.
Sturridge has been plagued by a series of injuries which have restricted him to 18 appearances in 2015.
"Everyone wants him back on the pitch but we all have to learn," said Klopp.
Speaking before Sunday's game with Swansea (16:15 GMT), he added: "The situation is Daniel was very often injured in the last few months, and maybe years, so it is normal when you get back in training usually it is not the quality, but you need training.
"Your body has to learn to adapt to new intensities of training and in this time you have to learn what is serious pain and what is only pain."