Salah's left-footed curler from a corner on the right side helped Egypt to a 4-1 win over Swaziland.
Assistant coach Hany Ramzy told Egyptian newspaper Al-Ahram he thinks "it is only a muscle strain but he will undergo medical scans to determine the length of the injury".
Salah sustained a muscular injury during Egypt's 4-1 victory over eSwatini in the Africa Cup of Nations qualifiers.
Liverpool fans would have been encouraged after Salah found the net for his country in incredible style, albeit against a side ranked 136th in the Federation Internationale de Football Association rankings.
Dodgers tweak lineup to adjust to Braves left-hander Newcomb
Newcomb, who pitched two innings of relief in Game 1, lasted 2 2/3 innings in Game 3 and was charged with two runs (one earned). Although it took four games, the Los Angeles Dodgers handled the Atlanta Braves with relative ease in the series.
Liverpool entered the global break third in the Premier League, level on points with Manchester City and Chelsea but behind them by virtue of their slightly inferior goal difference.
Liverpool legend Robbie Fowler believes Salah - who the title hopefuls will hope is fit to face Huddersfield a week today (5.30pm) - has not had as below-par a season as has been made out.
Salah appeared to pull up with a hamstring problem as the game entered stoppage time.
If Tunisia beat Niger tomorrow then the Pharaohs would hold a five-point cushion to Swaziland in third. The top two teams in each group qualify for the African Cup next June and July.
Angola and Cape Verde also boosted their campaigns with wins with teams midway through a run of seven straight days of qualifying matches.