He said although the club still had quality players, it was a big mistake selling the duo.
"It is a big mistake to sell them - they were the most important players last season,"Eduardo told BBC Sport.
"But they have other quality players to stay as a big club at the top."
"Every player comes to Arsenal as a simple player and Arsenal make them into a big player,"said Eduardo, who joined Arsenal from Dinamo Zagreb in 2007 and was sold to Shakhtar Donetsk in 2010.
"But they can't keep everyone together to fight for tit...