Still hospitalized with blood clots in his lungs, Pinkston was placed on injured reserve Monday, ending his second year in the NFL after six games. The 25-year-old was rushed to the Cleveland Clinic on Thursday with the life-threatening condition. He had been feeling poorly for most of last week and became ill during the previous Sunday's home game against Cincinnati.
Pinkston expected to be released, but he's still receiving treatment.
"My blood is just not quite therapeutic yet for me to leave and just continue on medications," Pinkston wrote on his Twitter account.
Pinkston also posted a photograph of a view from the hospital's roof, and said Browns president Mike Holmgren "stopped by and brought me a ton of stuff that was pretty awesome."
Pinkston started all 16 games as a rookie last season. The fifth-round pick from Pittsburgh had started Cleveland's first six games before missing Sunday's loss at Indianapolis. John Greco filled in for Pinkston and likely will start the remainder of this season.
Greco spoke to Pinkston and is confident his teammate will return when he's healthy.
"I don't even think that's a conversation where he's talking about being done," Greco said. "I know he wants to be out there as soon as he can. Like I said all along, Jason's just trying to figure out what's going on with him right now, and we're behind him. So anyway we can help, I will."
To fill Pinkston's roster spot, the Browns signed offensive lineman Jarrod Shaw from the practice squad. Shaw spent all of last season on Cleveland's practice squad and the first seven weeks of 2012. The 6-foot-3, 316-pounder played both guard spots and tackle in college at Tennessee.
Also, the Browns signed offensive lineman Bryant Browning to the practice squad. The 6-foot-4, 325-pound Browning played at Cleveland's Glenville High School and made 40 starts at Ohio State. He spent the first five weeks this season on Carolina's practice squad before his contract was terminated last week.