  The restricted online Ramsey numbers were introduced by Conlon, Fox,
Grinshpun and He in 2019. In a recent paper, Briggs and Cox studied the
restricted online Ramsey numbers of matchings and determined a general upper
bound for them. They proved that for $n=3r-1=R_2(r K_2)$ we have
$\tilde{R}_{2}(r K_2;n) \leq n-1$ and asked whether this was tight. In this
short note, we provide a general lower bound for these Ramsey numbers. As a
corollary, we answer this question of Briggs and Cox, and confirm that for
$n=3r-1$ we have $\tilde{R}_{2}(r K_2;n) = n-1$. We also show that for
$n'=4r-2=R_3(r K_2)$ we have $\tilde{R}_{3}(r K_2;n') = 5r-4$.
