COLLEGIATE BESTS:
| Event | Score | Date | Site/Opponent |
| 100 Breast | 53.87 | 11/21-23/24 | Ohio State Invitational |
| 200 Breast | 1:59.24 | 12/3/23 | Big Al Invitational |
| 200 IM | 1:46.10 | 12/1/23 | Big Al Invitational |
| 400 IM | 3:48.98 | 3/1/24 | B1G Championship |
2024/25 (Sophomore):
- Navy (10/4): Touched third in the 200 IM with a 1:52.55.
- Pitt (10/25-26): Finished fourth in the 100 Breast with a 55.97.
2023-24 (Freshman):
- Navy (10/7): Posted a third place finish in the 200 Breast with a 2:04.60.
- Big Al Invitational (12/1-12/3): Swam a personal best time of 1:46.10 in the 200 IM, good for a fourth place finish and NCAA B Cut. Added another third place performance in the 400 IM with a 3:49.48, good for an NCAA B Cut. Tallied two other career bests in the 100 Breast with a 55.10, and the 200 Breast with a 1:59.24.
- Army (1/12): Touched fourth in the 200 IM and 200 Breast.
- B1G Championship (2/29-3/2): Competed in the 200 IM and 200 Breast. Added a personal best finish in the 400 IM with a 3:48.98, good for a B Cut finish.
High School
During Slavica's high school career at Ekonomaska, he was a Croatian national record holder.
Personal
Slavica is the son of Marijo and Ivana and has a younger brother David. Before attending high school, Slavica swam for his hometown club of PK Sibenik.