Jamaal Lascelles is keen to lead Newcastle United in the Championship.
New signings Dwight Gayle and Matt Ritchie were among the scorers at Dalymount Park, where Newcastle were backed by around 400 fans.
Lascelles showed leadership on and off the field in the latter part of last season, when the team was led by Moussa Sissoko.
And the defender is favourite to get the captain's armband for the new season should Sissoko leave the club this summer.
"Rafa's got a lot of faith in me, which is a massive confidence-booster for myself," said Lascelles.
"I managed to get on the captain's armband today, which I was really pleased about.
"This shows how much trust he's got in me.
"If he makes me the captain, I'll be over the moon, but if not, fair enough. But either way, I'm still going to be vocal and class myself as a leader."
Asked if he had spoken to United manager Benitez about the captaincy, Lascelles added: "We've not spoken about it. I'll be happy either way. The main thing is getting results."
Lascelles handed the captain's armband to substitute Jonjo Shelvey after his withdrawal late in the game.