Although trade talks involving Philadelphia Phillies closer Jonathan Papelbon have stalled as of late, general manager Ruben Amaro hinted that a deal can still happen before spring training.

The Phillies were in "serious discussions" with the Milwaukee Brewers about a trade a couple of weeks ago, but talks soon slowed down because of an issue involving Papelbon's $13 million vesting option for the 2016 season. If the right-hander finishes 48 games in 2015 that option will kick in and increase his cost to $26 million over the next two seasons. The two seemingly could not agree on a dollar amount the Phillies would cover if that option were to vest.

The Toronto Blue Jays were also said to have interest in Papelbon, but it was considered "mild" due to the costly vesting option and their tight payroll situation. Sources said earlier in the offseason that the Blue Jays had about $5 million to $7 million left to spend, which would really put them in a tough spot if they were to absorb all of Papelbon's $13 million salary for 2015.

Those are the two clubs whose discussions were disclosed by sources over the past couple of weeks. Amaro spoke with Jim Salisbury of CSN Philly on Monday and here's what he had to say:

"Things are still alive. We're still having discussion - and not just with one club."

As for his optimism about a trade being executed...

"I'm not sure. We'll see. It's complicated. There are a lot of different factors involved."

Salibury noted that Amaro would not name the clubs the Phillies were talking to, but sources have said the Brewers are the frontrunners to land the closer. However, Jon Heyman of CBS Sports makes a good point about how Philadelphia might be disadvantaged if that were the case.

"One other issue for the Phillies is that K-Rod [Francisco Rodriguez] is still available, and that's the guy Milwaukee had last year and has had in the past. They do like [him]," he said on MLB Network's Hot Stove. "[Rafael] Soriano is still out there, so there are other options for the Brewers."

There aren't many other teams left who are in need of a $13 million closer, but perhaps a couple, most notably the Houston Astros, should take a look. First off, they have the financial flexibility to take on Papelbon's contract since their estimated total payroll for the 2015 season is only $63 million. Houston did sign Luke Gregerson and Pat Neshek this offseason to bolster their bullpen, but neither have sufficient experience as a closer. Additionally, the Astros had the worst bullpen ERA (4.80) and led the league in blown saves (26) this past season.

Could the Astros be one of the other clubs the Phillies are talking to?

It was noted earlier in the offseason that Houston was not willing to meet Amaro's demands for Papelbon, but perhaps his asking price was lowered after the market proved to be almost nonexistent.