NEW YORK (Reuters) - NFL plans to expand the regular season by two games could derail contract talks unless health and safety issues are satisfactorily addressed, player representatives said Tuesday.

Baltimore Ravens cornerback Domonique Foxworth and Cleveland Browns linebacker Scott Fujita of the NFL Players Association's executive committee, said players are preparing for a lockout once the current labor agreement ends in March.

"We're just not going to budge on health and safety and we'd like to gain more ground on ways we can protect former players and current players," Foxworth told reporters in a conference call.

NFL Commissioner Roger Goodell issued an open letter to fans earlier this month expressing confidence that an agreement with players would be reached and that adding two games to the 16-game regular-season schedule was a key element in talks.

NFL owners support the idea of adding extra games during the regular-season and axing two of the four pre-season ones -- when competition is less intense and starters generally do not play full games.

Fujita, as well as Foxworth, had his season cut short by injury and estimated that over 350 players finished the season on injured reserve and that more players would be put at risk with an expanded schedule.

"The way the 18 games so far has been proposed, (there is) no consideration of change in benefits and no consideration for changing post-career benefits making sure our players are taken care of in the long haul," Fujita said.

"The future welfare of us and our families needs to be considered. For us it's disappointing and feels like a slap in the face."

Foxworth agreed.

"After we retire we get five years of health insurance," said the Ravens cornerback, who added that many health issues stemming from football arise after that period. "And then they want to tack two more games on top of that, which will just multiply the number of injuries and ailments."

(Reporting by Larry Fine, Editing by Frank Pingue)