The Egypt international scored twice in the Red's win over Southampton on Saturday, taking his tally to 14 goal in 18 matches in all competitions this season.
With Champions League qualification up for grabs and a tricky December ahead, Henderson knows Salah maintaining his prolific streak in front of goal will be key.
"I just want him to keep going. He hasn't taken his foot off the gas. He's working hard in training and in the games. It's not just his scoring it is his work-rate," Henderson told the club's website.
"He has been brilliant for all the season so far. He has to keep it going for us like all the players but it is a good start coming back after the international break.
"It is important for us over this busy period, it's important to keep players fresh and raring to go - even those who are not starting.
"The big games keep coming but that is what we have to prepare for. We knew the next couple of months would be big for us.
"It was important after the [international] break to start well after all the good work we've done beforehand because sometimes it is difficult to get that momentum going when the lads have been away for some time.
"But there's still a lot of work to be done."