On the bench for the matchday 16 fixture at London Stadium, the 25-year-old emerged as the go-to man when left-back Patrick Van Aanholt pulled up injured in the 55th minute.
In the end, the Black Star, who can also play in midfield or in attack, was among the scorers of The Eagles' consolation goals in what ended in a 3-2 defeat.
"I've been ready when called upon to come in and play at left-back or left-wing," Schlupp told his club's official website.
"I've helped the team when I've needed to.
"I've had to do that from the bench in recent games but I've been ready and waiting and I've played at left-back before.
"I played there quite a bit last season and I was ready to slot in there and do the job that Patrick's been doing so well."
Interestingly, it was 16th-placed Palace who scored first through James McArthur before Robert Snodgrass, Javier 'Chicharito' Hernandez and Felipe Anderson hit back for West Ham with three goals after recess.
"There's plenty of positives to take from the game still even though it's a disappointing result," Schlupp opined.
"We already know what we're capable of doing at home.
"We played Burnley last week, we got a great result and [had a] great performance.
"Obviously, with the fans behind us at home - and everyone knows the atmosphere they can create - hopefully they can be the twelfth man and get behind us."
Saturday's fixture was Schlupp's 14th league appearance - involving six starts - of the season. The goal was his second of the campaign.
Compatriot and club mate Jordan Ayew was also introduced in the second half - precisely in the 66th minute.