Roma is more then capable to stop United in Euro league,Strootman,Naingoolan,De rossi,Paredes in midfield and Salah,Dzeko in attack is quality team who actually play great,fluent attacking football this season.But its hard against Juve in league,they are such a consistent machine.Roma main problem historically is that mentality to fuck up when it means the most,they always 2nd.Dont know for sure but they probably hold record in 2nd places in Serie A.