It has emerged that the 27-year-old has been sparring with world title contender Kubrat Pulev of Bulgaria, who had been due to challenge Ukrainian giant Wladimir Kiltschko for his various titles on the same evening in Hamburg. However, the 38-year-old champion - and holder of the IBO, IBF, WBO and WBA belts - has pulled out as the result of a bicep injury and is to reschedule his defence for later in the year.
Cornish, who is bidding to become the first Scot to fight for the British heavyweight belt, has been assisting Pulev with his preparations prior to the bout being called off.
"Gary had been sparring with the likes of Tyson and Hugh Fury and Eddie Chambers, the leading American in the Fury camp, but he stepped up another level against Pulev, who is undefeated," said Tommy Gilmour, Cornish's manager.
Cornish - who boasts a perfect record of 18 wins, 10 of them inside the distance - relished the chance to test himself among such illustrious company. "Tommy getting me sparring against one of the top fighters in the world is a huge boost to my confidence," he added.
The late Ken Shaw of Dundee is the only Scottish heavyweight to have even come close to fighting for the Lonsdale Belt after he was beaten in a final eliminator in 1949 by Freddie Mills.
Cornish will be closer to realising his own ambition when he headlines in Paisley ahead of an impressive undercard. Colin Bellshaw, the Saltire Boxing promoter, confirmed last night that Cornish's bout - and the title eliminator between Scottish light-middleweights Kris Carslaw and John Thain - will be supported by Scottish welterweight champion and local fighter Craig Kelly, who takes on Marek Laskowski for the British Masters gold title.
Welterweight Matt McAllister, of Aberdeen, will also make his return following injury, while Stirling boxers George and James Thomson, and local middleweight Brian Peacock, will also take to the ring.