Hardly. Casilla's last 3 years are 3.45, 3.46, and 3.67 xFIP, and he appears to likely be an xFIP beater (3.19 career ERA, 3.93 xFIP in 555 innings). He has closing experience (which is always nice), and his velocity is still there. Very good curve and slider, K rate over 10 last year. Numbers were inflated by the home runs, which were at a much higher rate than normal for him.
Tolleson has put up xFIPs of 3.83, 3.31, 3.89 the last 3 years. Last year suffered the home run issues too (24% hr/fb). Controllable through 2018, also has closing experience and should be signable for very little.