Ulster captain Iain Henderson will miss his side's United Rugby Championship match away to Leinster on Saturday with a hamstring injury that will rule him out for a few weeks.

It was unclear at the time what the lock's problem was, but Ulster said on Tuesday that it was a hamstring injury.

Ulster will take on their inter-provincial rivals at the RDS Arena.

It will be a first competitive match since 23 October for Dan McFarland's men as the United Rugby Championship returns after a five-week break.

Leinster are top, having won all five of their matches so far in the first year of the competition, with Ulster in second with four wins from five outings.

Ulster lost their 100% start to the season on their last outing when a disappointing performance saw Connacht beat them 36-11 at the Aviva Stadium.

McFarland's men begin their European campaign against Clermont on 11 December and Henderson also could be an injury doubt for that match.

"I don't think we necessarily needed a break, not for four weeks anyhow, but we've had some good training and are really looking forward to getting back into it this weekend," said Ulster head coach Dan McFarland.

"We didn't perform anywhere near what we are capable of at the Aviva against Connacht. They played really well but we were all disappointed with how we played in that game. There was an acceptance it wasn't good enough.

"We now have a bloc of 10 games where we play seven different teams and it's a hugely challenging bloc - interpros, European games and then Ospreys and Scarlets to finish off is a huge challenge and will go a long way to defining our season."