Ingram is one of three New England rookies who haven't yet agreed to a contract. (Photo courtesy University of Hawaii.)

With rookies set to report to training camp early next week, a source indicated that the Patriots have hit a snag in their negotiations with at least one of their three unsigned rookies.

It was believed earlier this week there was cause for optimism surrounding the negotiations for sixth-round pick Jake Ingram, with one source expressing confidence to WEEI.com that a deal would be done “shortly.” But the talks between the two sides have apparently stalled over the proposed signing bonus.

A long snapper out of Hawaii taken 198th overall in the 2009 draft, a league source says Ingram — who is represented by the Morgan Advisory Group — is seeking a three- or four-year deal, a slotted contract that would give him a a signing bonus of roughly $95,500 on a four-year deal and $70,000 on a three-year contract.

However, the source indicated New England and senior football advisor Floyd Reese — who is taking the lead in contract negotiations — are attempting to take part of the signing bonus on a four-year deal and put it into a 2010 roster bonus. That doesn’t sit well with the Ingram camp.

The Patriots make it a practice not to comment on contract situations, and refused comment on the matter Wednesday afternoon.

It doesn’t appear to be a major sticking point, as the source “still expect[s]” the two sides to reach an accord relatively quickly. However, when compared to the relative quickness of the other negotiations — eight of the nine rookies agreed to contracts within a month’s time — it stands as a bit of a contrast.

Ingram is one of three members of New England’s 12-man draft class who remains unsigned. Second-round pick Patrick Chung and third-round selection Tyrone McKenzie also remain without a deal, although McKenzie reportedly suffered a season-ending knee injury in rookie minicamp, which would remove some of the urgency to get a deal done with the South Florida product.

Ingram was regarded as one of the best college long snappers in the country last year. He is expected to vie with Nathan Hodel to replace veteran Lonie Paxton, who signed a free-agent deal with the Broncos during the offseason.