James Marsden has said he wanted to do a really good job in his latest film after stepping in to replace the late actor Paul Walker.

The X-Men star takes a leading role in romantic drama The Best Of Me, based on a novel by Nicholas Sparks. He plays oil rig worker Dawson, who is reunited with a former childhood sweetheart (Michelle Monaghan) after the death of a mutual friend.

The role of Dawson was originally intended for Fast And Furious actor Paul, who was killed in a car crash last November.

"Paul was just a wonderful actor who was an even more impressive human being," said James. "You always want your work to be good anyway, but [there] was a little added incentive there, yeah."

The younger version of Dawson is played by Australian actor and former Home And Away pin-up Luke Bracey, and both actors have their fair share of shirtless scenes.

"Luke and I would see each other in passing. I'd see him working on his physique and I'd say, 'Stop working out, I can't keep up with you!'," James joked.

The 41-year-old screen heartthrob said growing older does have its perks though.

"When you're younger, you get cast a lot based on your looks. It's great to be able to get that work, and then get the opportunity to learn from it and prove you're not just that.

"The older you get, the more interesting the roles are. When you're young, you're playing the Romeo and Juliet and it's all love-driven and hearts coming out of your eyes. When you're older, there's more complexity to the way you show love, and what's carried with that, and there's a pain behind it sometimes."

:: The Best Of Me is released in cinemas on Wednesday, October 15.