Rangers face the Dons at Pittodrie on Wednesday in a key Premiership match. But Morelos has a poor disciplinary record against Aberdeen and the Ibrox boss might think about resting him, with one eye on the weekend showdown at Hampden.
Gerrard has made it clear to those who do start against Aberdeen that they have the chance to secure their place in his plans for the cup final with a big display.
"That's the message in all the games," Gerrard said. "I'm always saying that when you represent this club, you have to do everything you can to stay in the team.
"That magnifies it a bit with the game at the weekend but the players have only got to focus on the job I'm asking them to do against Aberdeen.
"It's not wise to think about the weekend. We need to go full-throttle from the kick-off and do everything we can over the 90 minutes, but you'll find out my team at 6.15pm tomorrow."
Rangers are unbeaten away from home domestically this season and Gerrard is confident his team will take their latest road trip in their stride - but he does want to risk a suspension scare.
Two of the five red cards Morelos was shown last season came at Pittodrie - although one was later rescinded - and the boss said: "We've been giving a message to the players since the issues we had last year.
"You can't take a competitive edge away from a player. We want them to compete and to be up for it, but you have to be disciplined as well and do it in the right manner. That's all we ask.
"We've got to thrive and embrace the atmosphere at Pittodrie.
"We've faced some real big challenges this year when you think of Feyenoord and Legia Warsaw away. I don't think any of my players will be shying away or intimidated by the atmosphere up there."