Ruiz told fulhamfc.com: "From what I have seen so far, they look really good. Sascha is a strong defender while, further forward, Mladen has done well too. He has scored a lot of goals so far, and hopefully he can continue to do so.
"Okay, they might be pre-season goals, but you can only score in the games that you are part of. As a striker, it will give him confidence going into his first campaign at the Club, and that is the important thing.
"Hugo [Rodallega] has come in as well, and we're looking forward to seeing him in action. He did well in his time at Wigan and, as a result, has Premier League experience. He'll be hoping he can make an impact too, and I'm sure he will be a success.
"It's nice to welcome new players. The spirit of the Team is really good and we are all looking forward to getting the season started. We had a good year together last season, and we want to do good things again."