There are second row forwards regarded as number four locks and others regarded as number five locks, but Anton van Zyl is one of those happy to move between four and five.

For those unfamiliar with the distinction, Victor Matfield would be your prototype five lock and Bakkies Botha a number four - which means that with Stormers kingpin Andries Bekker a five lock, what he needs next to him is a four lock to complement him.

De Kock Steenkamp was the Stormers selection initially at four with Van Zyl on the bench and regarded by some as a five lock and competing with Bekker for a starting spot, but since being given a chance to stake a claim at four, Van Zyl has not looked back.

He was superb for Western Province in the Currie Cup last year and has been in top form for the Stormers.

"I'm just loving being part of the team. I'm just keen to get out there," Van Zyl said, speaking after Stormers training on Wednesday.

Asked by iafrica.com whether he was happy to move between four and five, Van Zyl said: "Absolutely, without a doubt. My biggest thing is just to be in the team. I want to play a role. I'm not concerned about the number on my back. I'm happy to play whatever role the team needs.

"I'm pretty lucky that ever since I've started playing, I've never really spent a significant amount of time at either four or five. I've always been changed, so I think it has allowed me to gain a little bit of experience to play at both four and five."

The articulate 30-year-old - nicknamed Worms by his team-mates - is Cape Town born and bred but his first 30 Super 14 caps were for the Lions before he came back home to Cape Town ahead of the 2009 Currie Cup.

He is enthusiastic about the camaraderie of the Stormers forwards.

"I think part of our relative success as a pack has been our focus as a collective unit rather than as eight individuals."

While he appreciated the particular role he had to play in scrums and line-outs along with Bekker, he saw himself "as part of a big picture".

Asked about the Stormers ability to steal opposition line-out ball, he praised the preparation done by the team's video analysts and coaches before each game.

But the Cheetahs would provide a tough line-out challenge.

He said former Springbok Barend Pieterse, who has come out of retirement and is on the bench on Saturday, had been running the Cheetahs line-outs for the last few years, lately as their line-out coach, "and you can see his influence very clearly in their line-out".

"I think they've had one of the most effective line-outs this year in the Super 14," said Van Zyl, adding: "They're very good at getting their middle and back ball.

"That's a lot to do with Barries [Pieterse] being quite a keen student of the line-out."

He said he thought the Cheetahs would miss David de Villiers (injured shoulder), who had taken over Pieterse' role in the second row and done an excellent job as five lock, "but Waltie Vermeulen is not exactly a slouch either".

"It'll effect them from an experience point of view," Van Zyl said, "but with Barries on the bench and Nico Breedt at number four, I dont think it'll have such a major effect."

Van Zyl lauded his fellow Stormers lock Bekker: "Andries is a world-class lock; he's just getting better and better. He could almost have been man of the match in just about every single game. One can't underestimate his influence in our team. It's fantastic having him around."