Elliott, an All-Star last season, rebounded after a slow start to this season and played a significant role in the Blues' push into the playoffs.
Many believe the Blues will entertain offers for either Elliott or Halak, though Halak could be more available if the right offer comes across GM Doug Armstrong's desk.
The Blues do not need to act on a move just yet though, as Allen can still be send down to the AHL without having to clear waivers. However, the Blues are looking to make some upgrades up front and could dangle Halak or Elliott.
A number of teams will be looking to make a move in goal this summer, but there are a number of netminders available in the market.
Vancouver is expected to trade Roberto Luongo this summer, while the Buffalo Sabres are expected to do the same with Ryan Miller. Los Angeles Kings backup Jonathan Bernier is also likely to be dealt.
With Martin Brodeur playing one more season in New Jersey, the Devils will be looking for a young backstop this off-season, but could target someone like Bernier or Allen over Elliott or Halak.
Armstrong isn't itching to pull the trigger on a deal, but will consider all options heading into the summer.