Both Grilli and Richardson cleared waivers, but the Rangers expect Grilli to decline the assignment and become a free agent. Richardson could sign a minor league deal with the team.
On his Twitter page, Grilli wrote: "Team #7 possibly? We shall see-Ah the joys & glamour of the baseball business. I LIVE 4 THIS! Gonna be some Rocky Balboa training commence."
The Rangers acquired Grilli from Colorado for cash considerations on June 9. He was 2-2 with a 4.78 ERA in 30 outings with Texas. His first 17 appearances were impressive, as he had a 1.53 ERA and opponents batted just .150 against him. But right elbow inflammation slowed the second half of his season and he allowed runs in six of his last 13 outings.
Richardson made his major league debut this season and was 3-for-6 in four games, including one start.
The Rangers now have 38 players on the 40-man roster.
Richard Durrett covers the Rangers for ESPNDallas.com. E-mail firstname.lastname@example.org.