The Mets and Rockies have had discussions throughout the offseason about a deal that would bring superstar shortstop Troy Tulowitzki to Queens, and according to a source, those conversations likely will continue through the winter.

Multiple sources, however, said Friday that the chances of a blockbuster trade coming together are remote, with numerous hurdles left to clear before an agreement is reached.

Money is perhaps the biggest barrier. Tulowitzki is due $118 million through the 2020 season and, according to a source, the sides have yet to discuss financial parameters.

The Rockies have offered no indication of how much money they would be willing to absorb in a trade of their star. Finances have been a critical issue for the Mets, who have shown no signs of deviating from the payroll range of $90 million to $100 million that they've established in the last four seasons. And the dollars involved will hinge on another potential sticking point: the exchange of young talent.

A source said any deal almost certainly would require the Mets to include multiple high-end prospects, including pitcher Noah Syndergaard. Earlier Friday, CBSSports.com reported that Syndergaard is at the center of the talks. With the Mets' payroll expected to remain in the same range, parting with cost-controlled talent could leave them vulnerable in the long run.

Tulowitzki's injury history adds another element of risk for the Mets. The 30-year-old still is recovering from surgery to repair a torn labrum in his hip.

Then again, the Mets could be rewarded for the risk at a time when they believe they are on the brink of returning to contention for the first time since 2008.

Tulowitzki is a two-time Gold Glove shortstop and one of the best hitters in baseball. The four-time All-Star hit .340/.432/.603 in 91 games before his hip injury cut his 2014 season short.

His success also has translated outside of hitter-friendly Coors Field. In 14 games at Citi Field, he has a .438/.534/.833 slash line, having gone 21-for-48 with five homers and 11 RBIs.

The Mets have searched for an upgrade at shortstop over the defensively deficient Wilmer Flores, but finding an alternative has been difficult.

They passed on one potential option at shortstop. As expected, according to a source, the Mets did not submit a bid by Friday's deadline for exclusive negotiating rights with South Korean shortstop Jung-Ho Kang. Like many scouts, the Mets have concerns about Kang's defense and whether his offensive ability would translate against much tougher competition in the major leagues.

But in at least one instance -- their pursuit of Jimmy Rollins -- the Mets were rebuffed. The former Phillies star briefly was under consideration earlier in the offseason. But according to a source, when the Mets inquired about him, they were informed that he would not waive his no-trade clause.

Speaking publicly Friday, shortly after his trade from the Phillies to the Dodgers became official, Rollins seemed to dispute that. He told reporters that he would have accepted trades to the Mets or Yankees.

It proved to be a moot point for Rollins, who said his first choice of a landing spot was the Dodgers, where he ultimately wound up.

For the Mets, the status quo remains. Flores appears the prime candidate to start at shortstop, with other options increasingly out of reach.