Salah had to leave Saturday's 3-1 victory over Crystal Palace after just under an hour with an injury.
The 33-year-old Egyptian star will leave Liverpool at the end of the season and now it will be a race against time to see if he can play more for Liverpool. The reigning champions play their final match of the season at home against Brentford on May 24.
Egypt national team doctor Ibrahim Hassan told Saudi newspaper Okaz that it is a muscle injury and that it requires four weeks' rest. When asked if Salah can play in the season finale, he said:
It is not possible to answer this at the moment.
Mohamed Salah has scored 257 goals in 440 matches during nine successful seasons at Liverpool.
