Injection-and-recovery test performed to check the detectability of additional planets in the TOI-2015 system. We explored a total of 6000 different scenarios with the orbital period ranging from 0.5 to 15 days and radius from 1 to 5 R_⊕. Larger recovery rates are presented in green and yellow, while lower recovery rates are shown in blue and darker hues. Planets larger than 3.0 R_⊕ with P ≲ 10 d would be easily detectable. Planets below 1.5 R_⊕ would be undetectable, with recovery rates lower than 20% in all cases. The dashed red lines show the MMR possibilities for the non-transiting planet. The blue dot refers to the planet TOI-2015 b.