The 19-year-old has played the second fiddle to Ibrahimovic for most of the season, but he has been leading the United line of late in the absence of the injured Swede.
The United youth product scored a stunning free kick in the 1-0 Europa League win over Celta Viga on Thursday.
After the game, Ferdinand said on BT Sport: "There's a contrast between him and Zlatan.
"Having Zlatan in the team you've got them 20-odd goals this season. But in terms of giving you all-round performance, hustling and bustling defenders, running in behind and stretching teams, Zlatan doesn't do that. He's not at an age where he can do that.
"This kid does. He gives you something extra and midfielders really appreciate that."
Owen added: "I think if you asked his teammates they'd probably prefer to play with Rashford up front because he gives them options.
"Zlatan will probably always score a few more goals than Rashford, if they both started every week, but the team would score a lot more with Rashford in."