Veteran outside linebacker Terrell Suggs, nose tackle Haloti Ngata and defensive end Chris Canty are attending the Ravens' mandatory minicamp after being absent from all of the organized team activities this spring.
Under the NFL collective bargaining agreement, one full-team minicamp is mandatory to attend or players can face fines approaching a total of $70,000.
Meanwhile, the Ravens are trying out former USC and Indianapolis Colts cornerback Kevin Thomas along with veteran cornerbacks Aaron Ross, Dominique Franks, Drayton Florence and Marquice Cole.
Thomas was drafted in the third round by the Colts in 2010, but missed his entire rookie season with a knee injury.
In 2012, Thomas was traded to the Philadelphia Eagles along with a conditional seventh-round draft pick in exchange for former Maryland linebacker Moise Fokou and linebacker Greg Lloyd Jr.
Thomas, 27, signed with the Toronto Argonauts of the Canadian Football League in April.
A 6-foot, 192-pound former SuperPrep All-American, Thomas has recorded 32 tackles in three NFL seasons.
Nose tackle Terrence Cody (hip surgery), offensive guard Jah Reid (calf strain) and wide receiver Kamar Aiken (strained lower leg) aren't practicing.
Cody isn't expected to return until training camp.