"He's a top quality player and after being with Atletico Madrid it won't be a problem for him," Reina said. "I expect him to score goals, he is learning English very early and has the mentality to succeed.
"I can't explain what he is going to find because I don't want to scare him. He will find out in his own way but I am convinced that he is absolutely ready to meet the challenge."
The 21-year-old turned in a string of inspirational performances during the Addicks' unsuccessful fight against relegation but Reina insisted he is ready to cope with the added competition.
"I think it's a great challenge for me," he said.
"The more intense it will be, the better for the team. I'm not worried. I know Scotty will be pressuring me, he's a great shot stopper and he showed that last season and it's better for the team."