Red Sox interim manager Torey Lovullo said Ramirez continues to progress, but is still feeling a little bit of discomfort. Castillo had his foot examined before Saturday's 22-10 victory over the Mariners.
"We are going to do right by these players," Lovullo said. "We want them to play at full speed without any limitations."
With restrictions on both players, the Red Sox added depth to the bench by recalling Garin Cecchini. He takes the place of Steven Wright, who was placed on the seven-day concussion disabled list Friday.
Cecchini is up with the team for the first time this season after playing in 11 games with the Red Sox last season. He's played left field, first base and third base for Triple-A Pawtucket.
"He's energized, he's excited and he is going to fill a void for us," said Lovullo.
Quinn Roberts is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.