[3] In 2009, Siegrist was part of his nation's FIFA U-17 World Cup winning side, during which he also received the competition's inaugural Golden Glove award for best goalkeeper.

During seven years in the Aston Villa Academy Siegrist undertook a series of short-term loans to English Football League and Conference sides.

[10] In March 2014 Siegrist joined Cambridge United of the Conference Premier, the fifth tier of English league football, on loan until the end of the season.

Siegrist joined Solihull Moors of the National League North on a one-month emergency loan on 8 October 2015 having recovered from a serious leg injury in May 2015.

[16] Siegrist was named man of the match in a 2–2 draw with Lowestoft Town on 7 November 2015, making a string of saves to keep Moors in the game.

[18] On 19 March 2016, Siegrist joined Wycombe Wanderers on loan until the end of the season as cover, ultimately only playing a single match.

[24] In June 2021, United rejected an official bid to buy Siegrist from English League One club Ipswich Town.

In 2012, Siegrist was chosen as a backup goalkeeper to Diego Benaglio for Pierluigi Tami's 18-man squad to represent Switzerland at the 2012 London Olympic Games.