Browns starting tight end Steve Heiden and punter Dave Zastudil were placed on injured reserve Wednesday, ending their seasons.
''Steve and Dave worked extremely hard this year and you don't like to see anyone's season end prematurely because of an injury,'' Browns coach Eric Mangini said in a statement. ''They both provided a veteran presence that will not be easy to replace.''
The Browns were awarded two players off waivers -- receiver Jake Allen from Green Bay and linebacker Arnold Harrison from Pittsburgh.
An 11-year veteran, Heiden suffered an ankle injury in Monday night's 16-0 home loss to Baltimore. He also underwent major knee surgery last December and may have rushed back too soon, landing on the inactive list for two games. In seven games (six starts), Heiden caught 10 passes for 73 yards and a touchdown.
Arriving in a trade with San Diego in 2002 and the second-longest tenured Brown behind kicker Phil Dawson, Heiden could be facing the end of his career.
Zastudil, an eight-year veteran, sat out against the Ravens with a sore right knee. He ranks second in the league in punts inside the 20 with 25. He averaged 44.7 yards on 49 punts with a 39.1 net.
The Browns signed punter Reggie Hodges Sunday and he averaged 38.6 yards on nine punts against Baltimore.
Allen, 6-foot-4 and 196 pounds, entered the league as an undrafted free agent with the Packers and spent most of his time on their practice squad over the past two seasons. Harrison, 6-3 and 241 pounds, appeared in 28 regular-season games and started two for the Steelers in four seasons, with 12 tackles on defense and 22 on special teams.