Kobe - Scotland's WP Nel says the enforced lengthy separation from his family that comes with being at the Rugby World Cup is a "mental battle" but also "part of the game".

The South Africa-born prop is the father of three children - nine-year-old Henre, five-year-old Arabella and Kayla, who was only born in July.

"The mental battle is always there," said the 33-year-old front-row powerhouse.

"You miss your family, you want them around you, but as a team we are close together and we are helping each other," he explained.

"Sometimes phone calls home can be difficult. The kids are getting emotional, it's getting long (the time away) but it's our job.

"Back home, even if you are a weekend away it's tough for the kids. They don't like it, but you somehow need to get around it. It's part of the game. That's why you're playing - for the family and for the team around you."

Scotland continue their quarter-final quest against Russia in Shizuoka on Wednesday, having beaten Samoa 34-0 last time out.

"The next game is on Wednesday so they (Henre and Arabella) will probably be in school," Nel said.

"The Samoa was game on Monday but I know my boy (Henre) will probably have watched it about 10 times by now, he will probably say to me what I did wrong."

He added: "I'll need to bring them back presents. I need to empty my cases and put some stuff in there. I have got the list on my phone, a big list. It's all the way from cars to dolls."

Russia, ranked 20th in the world, have yet to win a match at this tournament but have posed problems for all of their Pool A opponents so far, particularly up front and in the scrum.

"Their tighthead (Kirill Gotovtsev, who has also represented Russia in bobsleigh and wrestling) is playing well and is the anchor of the scrum," said Nel.

"You can see that everything revolves around him at scrum-time. He will be a big factor for us in our preparation."