Salah smashed an incredible 32 goals in 36 Premier League games in 2017-18 in his first campaign since moving from Roma.
In total the Egypt international netted 44 times in all competitions, a mark that saw him mentioned as a hopeful for this year's Ballon d'Or prize.
In 2018-19, however, he has struggled to show the same zip in front of goal, with seven strikes in 15 matches to date overall.
And after another blank against Arsenal in Saturday's 1-1 draw, Keown questioned his form in strong terms.
"I look at Salah, and he doesn't look the real deal for me," the former Arsenal defender said to BT Sport.
"When you really look at him, he was really quiet today. Something is wrong.
"Maybe the injury he has is affecting him and he doesn't want to get hurt. He's not really the same player."
The tie at the Emirates Stadium saw Liverpool take an outright lead in the Premier League title race, pulling one point ahead of fellow challengers Manchester City.
Liverpool's advantage could prove short-lived, however, as the Citzens are in action on Sunday, at home to Southampton.