He spent his first 5 years with the club as a reserve and didn't see a single minute of game time.
After starting the season as third-choice goalkeeper, an injury to first-choice Masaaki Higashiguchi saw Tajiri make the bench for the clash at home to Urawa Red Diamonds on 19 March 2017.
Starting goalkeeper Yōsuke Fujigaya got injured in the 73rd minute and Tajiri was brought on as a replacement with Gamba leading 1-0 courtesy of Yasuyuki Konno's goal earlier in the second half.
[3] That was to be his only appearance for Gamba in 2017 and he was then loaned out to J2 side Zweigen Kanazawa for the next 18 months where he could only play 9 league games before moving back to Osaka for the 2019 season.
The following year he played 13 times for Gamba Osaka's newly formed Under-23 side in J3 League.