Tigers and Ospreys face each other in the competition for the third time in five seasons and there has been little to separate them in previous meetings.
Tigers managing director David Clayton said: “Over the last few years there has been a growing rivalry between Tigers and Ospreys and Sunday’s game promises to be another cracking occasion.”
The game on Sunday (kick off 12.45pm) will mark the first European fixture in front of the new Caterpillar Stand and the extra capacity at Welford Road means even more supporters can enjoy the unique experience of Heineken Cup rugby.
Tickets are available from now up to kick off and are available on the Tigers website, by calling 0844 856 1880 or by visiting the new ticket office at Welford Road. The office is open until 5pm tonight, 9am-2pm on Saturday and from 9am on matchday for ticket sales and collections.
Clayton said: “One of our challenges this season is to try to stop people thinking that every Tigers game is sold out and encouraging them to get tickets later in the week or walk up to the ground on matchday.
“Before, that was not available but with an expanded capacity we can cater for more supporters.”