"(The NHL's trade window is) closed right now," Regier said, as quoted by the Buffalo News. "Once you get through the unrestricted market, there's a little bit of a secondary market. Then as you tail off in July, the lines go dead. The league, for whatever reason, really goes quiet.
"As you approach training camp, teams for the most part look at their young players, look at their own group and, like us, are trying to figure out who's going to play, who's going to fit, where are they going to fit, what will the needs be. Then the season begins and talks start again. In most cases, not a lot happens until you get closer to the trade deadline, where it ramps up again."
The Sabres have been entertaining calls for Miller and Vanek since last season. Both players are in the final year of their respective contracts and are scheduled to become unrestricted free agents in July 2014.
It's believed that neither Miller nor Vanek will re-sign with the Sabres, and as a result, have been shopped.
"There's a business that goes on that most people don't know about or hear about, and there's a lot of speculation and rumors out there of things that may or may not have happened. We're approaching it from the standpoint of Ryan's here, Thomas is here, they're both in the last year of their deals like a lot of other players in the National Hockey League, and they're ready to go to work."
Meanwhile, Regier hopes to have restricted free agent center Cody Hodgson locked up to a new contract by the time Sabres players begin skating Thursday.
"We continue to work on his contract," Regier told the News. "I've had conversations with his agent on a couple of occasions this morning. I spoke briefly with Cody. Both sides are working hard on this.
"The efforts that are being made by both sides would indicate that we want to get something done as quickly as possible. We're going to make every attempt to get him on the ice tomorrow."