- Bats Right, Throws Right
- Height 6' 1", Weight 162 lb.
Jiří Vavruša was 1 for 3 with a walk and a run as a catcher for the Czechs in the 2013 European Junior Championship. He backed up Martin Mužík.  In 2015, he made his Extraliga debut, hitting .321/.391/.464 for the Tempo Titans Praha.  The next year, he had a 6.48 ERA in limited time for Kotlářka Praha. He spent most of the summer in the US, going 5-3 but with a 8.73 ERA for Trinity International University, while hitting .308/.357/.308. 
He improved to 5-4, 3.06 his second season for Kotlářka Praha.  He had a 6.00 ERA for the Czechs in the 2017 U-23 European Championship.  In '18, he faded to 2-2, 7.35 in the Extraliga. He still got to pitch for the Czechs in three tournaments that year. In the 2018 World University Championship, he was 2-0 despite a 6.55 ERA, beating Australia and Russia. He tied Japan's Hiromu Ise and the USA's Daniel Hegarty for the most wins. 
He debuted for the Czech senior team at the 2018 Super6. Against the champion Netherlands, he relieved Petr Minařík with a 7-1 deficit in the 7th and walked Dudley Leonora on seven pitches but then got Curt Smith to hit a comebacker for a double play. Kalian Sams reached on an error Vavruša retired Randolph Oduber on a fly. After the Czechs pulled with in 7-6 in the 8th, Ondřej Satoria took over on the hill. He did not fare as well in his other outing, versus Italy, but none of his moundmates did in a 25-10 loss. He took over for Daniel Padyšák in the bottom of the 4th with two on, two outs and a 18-7 deficit. He allowed a run-scoring single to Mattia Reginato and a threw-run homer to Nicola Garbella before Drew Maggi grounded out. In the bottom of the 5th, he retired Alessandro Vaglio but Alex Liddi singled, Chris Colabello went deep and Giuseppe Mazzanti doubled. Robel Garcia grounded the runner to third, then Beau Maggi singled to make it a mercy rule loss. His 22.50 ERA for the event was not the highest on a struggling Czech staff; three other hurlers were higher. 
Finally, in the 2018 U-23 Baseball World Cup, he was 1-0 with a 6.00 ERA, getting the lone Czech win (over the Netherlands).