Having worked with Bale at international level, Hartson has no doubt he could cope with a switch to the nine-time European champions.
"It wouldn't be an issue for Gareth," he told BBC Wales. "He's very level headed, his feet are firmly on the ground.
"I get to see him close up, obviously, working with him with the Welsh national team.
"He comes along to the squad and he works like all the other players, he gets his head down.
"He's got a great family. He doesn't come with a big entourage.
"He's got his agent, he's got his advisers and he's a really down-to-earth, level-headed lad and I think whatever Gareth does I'm sure he would have thought long and hard about it.''