He said: "They're both easy characters to handle. I always found Carlos to be no problem at West Ham.
"It was difficult when he and Javier first came because he wasn't fit and was just finding his feet in the Premier League.
"Carlos went a lot of games at West Ham without scoring but was always going to be quality.
"He was one of the few Argentinians to go to Brazil and win the league. He was adored by the fans there, which is not easy for an Argentinian.
"Carlos then overcame some major hurdles when he came to West Ham but the problem we had with both players was that they hadn't trained and worked.
"They were coming to a team that was well set - and the manner in which they came in probably upset one or two as they were taking their place.
"It was difficult times for them and for me. But I really enjoyed working with them and it was obvious they had real talent."