Seven-time champion Schumacher last raced against Raikkonen in 2006, before the German retired from the sport.
Raikkonen, who finished second to Schumacher in the 2003 season, is back in F1 this year after a two-year hiatus, racing for the Lotus team.
“I’m happy for him, very happy for him,” said Schumacher at the end of the day at Jerez.
“It is the first day and let’s see at the end of the three days (Sic) and then we can make a proper judgement of what those times were worth. But I am really happy for the team and for him.”
He added: “It’s great to have so many world champions on the grid. It is going to be a good show for all of us.”