McGregor, ranked fifth among 145-pound contenders, is listed as high as a 12-1 favourite to dispatch No. 10 Siver in the main event of the televised UFC card at Boston's TD Garden. Many see Siver as a mere bump — albeit a hard-nosed one — in the road for McGregor, who is one win away from a title shot against champion Jose Aldo before a record crowd at an Irish outdoor stadium.
Siver (22-9 with one no contest) insists he does not feel disrespected despite having 18 UFC fights to four for McGregor (16-2).
"Not at all," he said via email and an interpreter. "It puts tremendous pressure on Conor. You have to understand that he's still a young, inexperienced fighter.
"Here you have everybody telling the story that he will absolutely run through me. His own team is predicting a win in the first minute. Do they not realize what kind of pressure that creates? It's created a situation where Conor's only option is a quick, decisive win. Everything else will be seen as a failure — and that is what I will capitalize on. I will take Conor into deep waters and drown him there."
A former lightweight now campaigning at 145 pounds, Siver has proved to be a tough nut to crack with seven wins in his last 10 (7-2 with one no contest). The 36-year-old Russian-born German is an active kick-boxer who throws a lot of unorthodox strikes and kicks.
Siver has landed 712 significant strikes, the 10th most in the modern era of the UFC and is fifth in total strikes landed with 1,351.
Both men fight fast. The 26-year-old McGregor, whose UFC dance card is admittedly short, averages 4.6 strikes landed per minute compared to 3.8 for Siver. The UFC average is 2.83.
The five-foot-seven Siver will be giving up two inches in height and four in reach.
Siver, the first German to headline a UFC card, says his arsenal and experience will make the difference Saturday.
"I've been hit hard before. I've been in situations and persevered through situations that have been far worse than anything Conor has ever seen," he said. "Striking is my game but what will win me this fight is my wrestling and my skills on the ground.
"The situation we're in right now reminds me of what happened when I was supposed to fight George Sotiropoulos in Sydney (at UFC 127 in February 2011). I was a lamb being led to slaughter and the result was a foregone conclusion. One of us is retired today, and it isn't me."
With three first-round stoppages in his four UFC fights (all wins), McGregor has been in control in the Octagon. He has faced just two takedown attempts, stuffing both.
He's never been put on is back and has been controlled by his opponents for just 22 seconds of his 21:58 in the Octagon and that came in the clinch.
"His performances in his last two fights (wins over Dustin Poirier and Diego Brandao) were impressive and Conor has a great future in front of him," said Siver, before adding a caution. "I do believe that he believes his own hype, and if I have anything to say about it, he will not be able to live up to it."
McGregor has shown Siver little respect, tweeting "This will be a 2 minute Demolition Job."
Siver has largely resisted the temptation to engage verbally with the Irish fashion plate although he did tweet a picture of a well-dressed Muppet — Oscar the Grouch — with the message "Nice suit u #lametrashtalker."
Siver knows it's a battle he can't win. He doesn't speak English. The UFC collects collections of McGregor's bon mots.
"That's just not what I am about," Siver said. "I do recognize that some fighters talk a good game. Personally, unless they do their talking in the cage, that doesn't concern me at all. We are all athletes looking to grow the sport of MMA. Me engaging Conor on his level would have gone against what I believe in as an athlete and a person."
A former master mechanic, Siver fights full time these days.
He is known for a his spinning back kick, a move that stopped both Paul Kelly and Nate Mohr.
Mohr dropped like a stone when Siver sank his foot in his liver at UFC 93. Kelly tumbled backwards at UFC 105, his face distorted in pain, and essentially gave up.
It's a move also favoured by McGregor.
Those two kicks netted Siver US$80,000 in bonus cheques. But he lost money after defeating Manny Gamburyan at UFC 168 in December 2013 when he tested positive for human chorionic gonadotropin (hCG), later blaming a supplement.
Siver was suspended nine months and fined $19,800 — 30 per cent of his purse. The win was turned into a no contest.
Follow @NeilMDavidson on TwitterSuggest a correction