The Mets and Blue Jays continued negotiating into the evening Saturday, working to finalize a major trade that would send Cy Young Award-winner R.A. Dickey to Toronto for top catching prospect Travis d'Arnaud, according to major league officials briefed on the process.

Talks had grown so intense by Friday that the teams exchanged medical records on some players involved, the officials said, and remained serious through Saturday. Two people with direct knowledge of the process call a trade "likely." So what's the holdup?

Not contract negotiations with Dickey; the knuckleballer had not yet begun discussing an extension with Toronto as of Saturday evening, sources said. Dickey is willing to sign an extension with the Blue Jays if he is traded there, and his asking price of about two years, $26 million is well-known, so it is possible that that the Mets will not need to grant a window for negotiating before completing a deal.

The delay, rather, involved discussions over the size of the deal. At one point a relatively simple trade involved Dickey, d'Arnaud and perhaps a few other prospects, the proposals had grown by Saturday to include as many as six or seven players.