The 26-year-old was substituted shortly after his error led to PSG's equaliser at Anfield on Tuesday, and Keown has now said that Salah has not yet fully recovered from his injury.
"People were telling me afterwards he could have had a hat-trick but I was delighted for him that he got one goal - you have to remember how little he has played for the first team recently".
Shaqiri looked likely throughout the opening exchanges and it was he who created Liverpool's opening goal.
Liverpool have won all six games this season to make a flawless start and look a dominant force even without their talisman on top of his game.
Manager Jurgen Klopp now has the luxury of a stronger squad at his disposal and he can afford to rotate, but Salah remains the most valuable player at the Merseyside club.
"I don't mean that with any negativity - we're delighted because we know his class better than most". I am fine with him, I think he is fine with me and the situation, so that's all.
"On the defensive side, the last two games he was outstanding, perfect", Klopp continued. "It is completely normal everyone expects that".
"Finishing is something you can never take for granted".
'Saints were not bad, they were really good, but maybe in the final third they were not the biggest threat.
Last weekend, Solanke was on target for Liverpool U23s in their 3-0 rout of Swansea City in the Premier League 2, which was his only appearance for The Reds teams this term.