Six Nations substitutions: How many changes can each rugby team make in the tournament?

RUGBY UNION teams are made up of 23 players - eight of which are substitutes or replacements.

Some players come off the bench due to injuries, while other substitutions are for tactical reasons.

A normal bench will consist of four forwards and four backs.

But this is not absolutely necessary and it is down to the coach's discretion as to who is included on a bench.

So how many subs can a coach introduce in the course of the game?

A coach can bring on all eight players, play a select few or play none at all.

But once a player is substituted they can't be brought back on to the pitch except for one of two reasons:

• Blood injury which requires urgent medical attention.
• A forward is required to come back onto the pitch to replace an injured front-row forward.

Tell me more about a 'blood substitution.'

This will result in the injured player leaving the pitch and being replaced with another player until the injury/blood is taken care of.

If the blood does not stop flowing, the blood substitution will become a normal substitution.

A serious blood substitution can result in the player being off the pitch for up to a maximum of 15 minutes after which it becomes a permanent substitution.

Smaller cuts may be taken care of within a few minutes with a bandage or Vaseline to stop the flow of blood.

Does anyone at the top of the game think eight subs is too many?

Yes. Former England and Scotland head coach Andy Robinson for one.

He says: "I would love for us to look at lowering the number of substitutions we could make and get replacements down to five.

"It’s tough now for players to stay on who aren’t substituted off. The last 20 minutes when there should be space to play into they find themselves running into 120kg players who have just come on the pitch.

"So whilst they are feeling tired these other players aren’t and I feel we put players at risk doing that.

“This is a game where you want to keep players on for 80 minutes. We don’t see that now as you can change half your side.

"I feel that may have an impact on the number of injuries that are potentially occurring."