The sources said the Eagles' basic answer to interested teams is that getting Foles is going to take more than the first- and fourth-round picks they received from the Minnesota Vikings for Sam Bradford prior to the start of the 2016 season.
The Eagles have not actively shopped Foles but are taking inquiries, the sources said.
Foles, the reigning Super Bowl MVP, stepped in for an injured Carson Wentz and led the Eagles to their first title since 1960, throwing six touchdowns and one interception in the postseason.
Executive vice president of football operations Howie Roseman said the organization intends to "keep as many good players as possible" when asked about Foles at the combine last week, adding that the current quarterback room featuring Wentz, Foles and developmental prospect Nate Sudfeld is "exactly what we're looking for."
Coach Doug Pederson left more wiggle room for a potential deal, saying, "We'd love to have everybody back, but we know the nature of the business."
The Eagles have plenty of incentive to keep Foles. Wentz is recovering from a torn ACL and LCL in his left knee that he suffered against the Los Angeles Rams in December. While optimistic that he will be back for the 2018 opener, the Eagles have no guarantee that Wentz will be ready for the start of the season. They believe strongly in having two strong starting options at quarterback -- a philosophy that was bolstered by how the 2017 season played out.
But they are leaving the window open a crack in the event that a team comes to the table with an excellent offer. The Eagles are projected to be about $9 million over the cap and are without a second- or third-round pick in April's draft. Roseman has expressed the need to add picks so the team can offset some of the large contracts on the books with more players on rookie deals.
Foles is entering the final year of his two-year contract and carries a cap hit of $7.6 million. Any team that acquires him -- especially for the type of compensation the Eagles are talking about -- will likely want assurances that he will sign an extension, adding to the complexity of a potential deal.