While the deciding third T20 match between the sides at Old Trafford had to be abandoned on Sunday, Brook was announced as England's leader for the upcoming five-match ODI series with Jos Buttler's calf injury ruling him out.
Brook's promotion, after just 15 ODIs and less than a year on from admitting he was "still trying to figure out the format" during England's dire World Cup defence in India, continues England's recent policy of blooding a new generation of leaders.
Ollie Pope stepped in for Ben Stokes during the recent Test series and Phil Salt deputised for Buttler during the T20s.
Brook, a former England Under-19 captain who acted as Northern Superchargers skipper during this year's Hundred tournament, was eager to throw himself into the role - seeking out caretaker coach Marcus Trescothick within minutes of the Old Trafford washout being confirmed.
"Harry texted me about 10 minutes ago and I said, 'I'm a bit busy at the minute. I've still got a bit to do'," Trescothick said.
"We've already discussed a few things in previous messages or in conversation. We've got a very good relationship already, so we'll carry that on.
"New captains come in with fresh ideas and approaches. They can test the water and see how it goes in terms of what lies ahead for them. It means you can plan ahead for the future a little bit easier."
Buttler revealed in an interview with Sky Sports Cricket he was already planning to lay down the wicketkeeping gloves in a bid to reinvigorate his own captaincy.
Either Salt or Jamie Smith - the men in possession in T20 and Test cricket as it stands - will get first claim on the role when the ODIs begin at Trent Bridge on Thursday.
"Salty has being doing it in T20s and Jamie is the Test keeper, so we've got really good candidates," Buttler said.
"If I was playing, I was going to give up the gloves, go to mid-off and see how that felt. If that's something that will help me in my captaincy, it's something I'm open to. I just want what's best for the team."