Dad's keepers felt the noise from the anticipated vocal crowd in the venue would be too much for the bird, who often stays in a room within the stadium when he's not at work.
After years of keeping smaller birds from inside the stadium Dad is used to moving out when the fans move in.
His keeper Phillipa said: "Dad is a very hard worker during the week and due to the big crowds that come in for events he tends to take the weekends off.
"He's a full time resident here at the Stadium and essential for keeping seagulls and any other birds out of the ground and especially off the grass."
Hawks have been used to deter other birds from landing within the grounds for eight years, to prevent soiling on the pitch and seating areas and ensuring none nest within the venue.
Ospreys prop Duncan Jones took the opportunity to introduce himself to the bird of prey on a recent visit to the Stadium and both Osprey and hawk seemed to get on superbly.
Cardiff Blues will take on the Ospreys in an all-Welsh semi-final, whilst Leicester Tigers and Sale Sharks meet in an all-English semi-final, with all four teams slugging it out for a place in the 2007 final.
Leicester Tigers v Sale Sharks: 2.30pm
Cardiff Blues v Ospreys: 5.15pm
For ticket information log on to www.millenniumstadium.com or call into the Millennium Stadium ticket Shop, 98 St Mary Street on Thursday and Friday (9.00am-5.00pm), Saturday (10.00am-5.30pm), or Gate 3 marquee on matchday from 10.00am-5.30pm.