The La Liga champions concluded their pre-season tour of Japan with a comfortable 2-0 win over an Andres Iniesta led Vissel Kobe on Saturday.
Goals from Carles Perez secured the warm-up win and post-match Valverde discussed the impact of his two signings.
On De Jong he said: “Today he played in a different position [than against Chelsea]. He played more as an interior with Sergi Roberto as the holding midfielder.
“We can now try him in both positions. He’s good on the ball and arrives into good positions further forward.
“We are lucky than he can play in both positions and we can rotate him. He offers us a lot of solutions.”
Griezmann has also looked very sharp since making his long-awaited move from Atletico Madrid and Valverde added: “It’s true that some players who are good fit in together easier.
“We will see the relationship socially and at the camp. We are excited for this opportunity.
“We believe in balance in the team, in front or in the back, he moves quick, he passes well, and finds space and this is what we were missing.”
Know more about Sport360 Application