Bath's Sam Vesty says new arrival Stephen Donald should not underestimate how tough the Premiership can be.
New Zealand international Donald, 27, has joined Bath on a three-year deal from Super 15 side Chiefs.
The World Cup winner will arrive at the Rec next week and will compete with Vesty, 29, for the number 10 shirt.
"When it comes to training and we'll be smacking bits out of each other he'll realise it's about the Premiership now," Vesty told BBC Points West.
"He'll be on a bit of a buzz as he's won the World Cup but then he'll train here and it will be wet and windy and maybe that buzz will go.
"It's very different to Super 15s - the length of season, amount of time you get off and the type of rugby that's played. The defences work so hard over here and they are very well organised, perhaps not like in Super 15s.
"The boys are bigger and heavier over here so you get a little bit more bruised. But I'm sure he's a big lad so I'm sure he'll be able to cope with it. If I can cope with it I'm sure he can."
Along with Donald, Vesty also faces competition from academy youngster Tom Heathcote.
Heathcote, 19, was brought in the game against Leicester after Vesty had suffered a head injury and went on to kick the winning points in the 26-25 victory.
"I was playing alright and then I got a knock to the head and Tom came in and played really well," added Vesty.
"With Stephen Donald coming in as well there's lots of competition. But that's what the squads need - it keeps you on your toes and that competition ultimately leads to playing well and success.
"It's the healthiest environment for a rugby team."