It also pledged to work toward playing fall championships in the spring.
Turner racked up 24 catches for 294 yards and one touchdown across his four years in College Park.
Maryland's 2021 recruiting class rises to No. 8 in the nation with Graham's commitment.
Three former Terps have seen game action in the 2020 MLB season.
The Big Ten halted play Tuesday, but it left open the possibility of conducting a spring season.
Six former Terps are currently active and playing in the WNBA's bubble.
The German started 18 games, and was an all-Big Ten second team selection in 2019.
Tagovailoa transferred from Alabama in May.
Jackson is one of four starters from last year's team to opt out.