Ex-boss Alan Pardew had concerns about Jonas Gutierrez's future at Newcastle four years before he was released, reports BBC Sport.
Pardew said the midfielder was unlikely to be a regular starter despite offering him a four-year deal in 2011.
The 32-year-old, who was released in 2015, is suing Newcastle for disability discrimination over how he was treated after being diagnosed with cancer.
"My particular concern with Jonas related to the low number of goals he scored," Pardew told a tribunal.
"He had scored only three goals in the 2010-11 season which, for an attacking midfielder, was well below what I would have expected."
Pardew, now Crystal Palace manager, continued to start Gutierrez during the 2011-12 and 2012-13 campaigns because of his "experience" but he only scored three goals in that time, which Pardew said was again below his expectations.
He added the signings of players including Yoan Gouffran, Moussa Sissoko and Vurnon Anita in 2013 then saw the Argentine fall out of contention for the first team - something Pardew said he told Gutierrez that summer.
"I was honest with him and explained he would not be a regular in my first team for the upcoming season [2013-14]," Pardew, who appeared on day three of the employment tribunal in Birmingham on Thursday, said in a witness statement.
"Jonas appeared to accept my decision and continued to train well.
"However, as expected after a difficult conversation like this, I felt our previous good relationship deteriorated from this point onwards."