23-year old McCarthy was used 13 times in the Premier League last season whilst Australian gloveman Federici appeared in 21 top flight matches and the pair are likely to fight it out under Nigel Adkins ahead of the 2013/14 season.
McCarthy, who is highly rated in England, says that the rivalry between he and Federici - with Stuart Taylor also vying for position - is certainly a healthy one.
"Me and Feds have been here a while so we have a really good relationship. Then Stu's come in for the last couple of seasons. We're a really tight group but obviously all of us want to play," he told the Reading Post.
"It's up to the manager to pick who starts and it's up to the other two to respect that.
"We never fall out about because we're not the one who makes the decision. We all like to try and push each other in training and get the best out of each other. I wouldn't say there's any sort of animosity. We're all great friends, we just all want to play."