The 31-year-old American centre-back was released by the Rams last month following an injury-hit 2014-15 campaign.
Whitbread, 31, joined Derby on a permanent deal last June after spending three months on loan from Leicester City but a series of calf and hamstring injuries restricted him to just 11 total appearances during the 2014-15 campaign.
With the club since confirming his departure, the American defender is now on the hunt for a new challenge and, while he could continue in the English second-tier, a stateside switch is not out of the question either.
"We're in some discussions [with Championship clubs], but there is nothing concrete at this time," Moran said on Monday. "There is also some interest from MLS."
Born in Houston, Texas, but raised in England, Whitbread has never featured in MLS, having begun his professional career with Liverpool before going on to spells with Millwall, Norwich City, Leicester and Derby, respectively.
The ex-US Under-20 international has made 79 appearances in both the Championship and League One, as well as 18 in the Premier League, but it remains to be seen whether he will be adding to those totals or taking his talents across the Atlantic.
There are numerous MLS clubs who could do with an experienced stopper of his ilk on their backline but, as of this moment, it does not look like any have made a concrete approach ahead of the league's summer transfer window opening next month.