Didn't see the game tonight as I was watching our U23s. But you almost sound pleased with yourself.
Personally, I'm not overly surprised that Walsh, a 20 year old new signing playing in only his second full game for a championship club, failed to impress against a full strength Man City, far and away the best team in England, and arguably possibly the best club team in the world right now. If you seriously believe that him being substituted at half time tonight justifies our selling him, without giving him one opportunity in the first team, then maybe football isn't the game for you my friend.