Yu Darvish was not going to let a tornado warning interrupt his pre-start routine Monday in Chicago.
The Cubs’ game against the San Diego Padres was delayed as a large thunderstorm moved through the Chicago metro area, prompting multiple tornado warnings. Tornado sirens could even be heard at Wrigley Field, but that did nothing to stop Darvish, San Diego’s scheduled starter, from going through his routine.
https://twitter.com/sdutKevinAcee/status/1536489446148816896

We won’t say this is smart, but it certainly demonstrates commitment. Presumably, Darvish took shelter eventually once the pouring rains moved in.
Darvish spent three seasons with the Cubs, so he is at least somewhat aware that the weather in Chicago can sometimes make for wild playing conditions. Assuming the weather clears, he might have to deal with some less-than-ideal conditions once the game begins.