Clark has the sickle cell trait. It is a genetic abnormality which can affect red blood cells. While playing Denver in 2007, Clark had a bad reaction to the high altitude and had to have his spleen and gall bladder removed.
Meanwhile, Pittsburgh receiver Mike Wallace, who recently ended his holdout, has been working with the first unit and he should play extensively against the Broncos.
In other Denver notes:
Peyton Manning’s former Indianapolis coach Tony Dungy, was a visitor at the Broncos’ practice Monday.
Arizona signed receiver Gerell Robinson to its practice squad. Denver recently cut the Arizona State product.
The Broncos added former Mississippi State center Quentin Saulsberry to their practice squad.