As explained at https://developer.apple.com/documentation/combine/performing-key-value-observing-with-combine you can create a combine listener

statusObserver = player.publisher(for: \.timeControlStatus)
    .receive(on: DispatchQueue.main)
    .sink { newStatus in
        isPlaying = newStatus == .playing
    }

where isPlaying: Bool and statusObserver: AnyCancellable? are private @State properties on my view.