Two negatives have been turned into a super-sized positive by Glasgow Warriors in their recruitment of 19 stones plus South African prop Petrus du Plessis ahead of Sunday’s European Champions Cup opener against Saracens.

Injuries to international tighthead props Zander Fagerson and Siua Halanukonuka represented a major problem for the Pro14 Conference A leaders, but on joining Glasgow from English Championship side London Irish, the 37-year-old not only fills the breach in their squad, but brings considerable into insight into what will be required as not only a former Saracens player, but one who twice won the Champions Cup with them.

“I’m not sure if emergency is the right word (but) we’re obviously down our best two tightheads, we’re now heading into Europe and we’re only one more thing from being under massive pressure,” explained Glasgow’s head coach Dave Rennie.

“So, Petrus coming in gives us a lot of experience. We know that’s going to be important against a side like Saracens who have the ability to take care of the set piece and pin you in the corners. We were fortunate to get someone of his quality.”

While the necessary homework would always have been done on the reigning English champions and current Premiership leaders, Rennie acknowledged that

the veteran’s knowledge of the opposition could be a bonus.

“He’s played a lot of rugby for Saracens,” he said.

“The key for us is we need someone who can potentially give us an edge, especially at scrum time. Outside of that, he’s an explosive athlete, he’s a good man, he’s slotted in quickly.

“He’s very professional. He spent a big chunk of last night trying to get his head around a lot of the stuff we’re doing. It’s a big week for him.

“Look, we’ve got a lot of footage of Saracens. We’re pretty clear on the threats that they have and the opportunities that they pose. I’ve no doubt he knows a fair bit about individuals in their team and hopefully that will help him in his role for us, but we’re not leaning too heavily on trying to find out info from him.”

For du Plessis the move clearly represented an opportunity to revive his career at the top level and a chat with ex-Saracens team-mate and former Scotland captain Kelly Brown, who made his name in Glasgow, helped ensure he jumped at it.

“On Thursday evening I got a call from Dave and he was wanting to talk to me about where I am at the moment and what, as he would say, nick I am in, how much I have been playing and what I have been doing,” he said.

“I spoke with Kelly and he had nothing but admiration for Glasgow. He spoke really highly of them and said just as long as I could get my head around the weather. He gave me a lot of insight and it was all true when I got here. I’m thankful for that.”

That he will, on his first competitive involvement with his new club, encounter old friends with whom he shared so much only adds to his excitement.

“I enjoyed my time at Saracens. I was very fortunate to be there at a time when we won the (Champions) Cup twice. The pressures and the quality of rugby to win the cup… I have enough experience for that.

“What better game to go into for the Warriors than my old club. It is going to be a fantastic outing on Sunday, I am really looking forward to it.”

In terms of what he can tell his team-mates about what confronts them, there are no real surprises when facing England’s dominant club side.

“There is a good saying: you know exactly what they are going to do and you know exactly how to stop it, but you have to do it by being more physical, more urgent than them and do things better than them on the day,” he said.

However, he noted that Glasgow now boast more of a reputation in England than their repeated failures in the Champions Cup might be seen as meriting and suggested they have what is required to overcome the three-time former European champions.

“The two teams, for me, are very similar and want the same outcomes,” said du Plessis.

“They are dedicated to getting things right. I can imagine on Sunday it will come down to physicality and workrate.

“(In England) there is the utmost respect for Glasgow, same as you get when you talk about Leinster in the other table.

“I am used to the way Glasgow play as well. They are doing things right, that is why they are sitting where they are in the table. The coaches are doing a great job and from that point of view the Premiership knows what Glasgow is all about.”

He consequently believes Glasgow should be entering the competition believing they can win it, saying: “I’ve spoken to a lot of players who have played here quite a lot and they feel like the club has come a long way in the last few years and it’s brilliant to see.

“There’s no real recipe for who can end on top when it comes to the European Cup. However, I would say that culture plays a massive role and the culture that Glasgow have at the minute, the boys are tight. They get on really well, they look after each other off the pitch and on the pitch and that’s a good starting point. That’s where I think Glasgow is doing things right.”