They used to be called the “Greatest Show On Turf” and technically the Rams will still play on turf—just not the same kind. The AstroTurf at the dome is going to be replaced this year with the softer FieldTurf. An official announcement will be made this afternoon in St. Louis. Rams head coach Mike Martz complained loudly about the surface in 2004. He blamed running back Steven Jackson’s knee problems on it.

AstroTurf, is known as a much faster playing surface, which served the Rams well during their run to two Super Bowls in three seasons. The knock against AstroTurf is that the traction it provides, can also pose dangers because it doesn’t give as easily when a player is hit in the leg. Instead of sliding across the surface during a hit, a player’s foot is more likely to plant, which increases the chance of an injury. The padding underneath the turf at the dome had worn away, allowing almost no cushion when a player landed on it. The Rams were the last team to play on it.

FieldTurf plays similar to natural grass and is much softer than AstroTurf. It was installed at Faurot Field, the home of the Missouri Tigers, before the 2003 season. The Colts will also replace their AstroTurf with FieldTurf this off-season, which means 22 of the 32 teams in the league will have FieldTurf.