Striiker
Earthquake Survivor
The problem with Medvedev is simple, he's 33, not 23.
Which means the mistakes that you'd be patient with if he was 23 you won't tolerate when there's no upside.
Age is irrelevant when we're talking about right now, nobody is suggesting signing him to a long contract. All that matters is that right now he's better than Manning and should be playing. Both make mistakes all the time, but at least Medvedev can help the team in other ways to start to make up for it. Manning doesn't.