The front-row internationals also talk about the highlights in their first year at Welford Road, including the win in Munster and Castros first try for the club The one with the photo with my arm in the air! he says.
Ayerza describes how he overcame nerves to settle into full-time training at the home of one of Europes biggest clubs and end his first season in front of 82,000 people at Twickenham.
Tigers flanker Ben Herring also talks about the lure of the northern hemisphere and the differences between playing No7 in New Zealand and in Europe.
Also in Saturdays matchday programme:
Four-page guide to England Saxons versus Ireland A at Welford Road, including a welcome back for Tigers favourite Graham Rowntree
£300 of NEXT vouchers to be won
Head coach Marcelo Loffredas comments ahead of the crucial clash with the Falcons
The story of Newcastles season so far and guide to their top men
Tigers Development XV & Academy updates
Fanzone featuring Tiger Hunt, Dream Team and Theres Only One Alex Moreno
All in the 92-page Tigers matchday programme, available throughout Welford Road, price £3.