5:08pm: Niese's contract extension would be for five years, a source confirmed to Mike Puma of the New York Post (via Twitter). The two sides are still discussing dollars and a deal could be reached "quickly".
4:10pm: While nothing is official yet, the contract has a chance to be completed before Opening Day, a source with "direct knowledge" of the talks tells Andy Martino of the New York Daily News (on Twitter).
3:48pm: Brian Costa of the Wall Street Journal tweets that the paramaters for the contract are in place, but that it'd be wrong to suggest that it's a done deal. Costa does say that a deal is "likely," however. Rubin echoes the sentiment in a followup tweet.
Rubin writes that Niese's contract is believed to be similar to the five-year, $28.5MM extension that Derek Holland signed with the Rangers last month. As Rubin points out, the two have similar service time to date. Niese, like Holland, was already under team control for four more seasons.
Niese posted a 4.40 ERA in 157 1/3 innings of work last season with solid rate stats of 7.9 K/9, 2.5 BB/9, and a 51.5% groundball rate. He was the victim of some bad luck, as evidenced by an above average .333 BABIP and an abnormally low 67% strand rate. Stats such as FIP (3.36) and SIERA (3.42) suggest that his ERA could have been up to a full run lower.
The deal would likely represent the largest contract extension of general manager Sandy Alderson's tenure, as MLBTR's Extension Tracker shows. Previously, Alderson has agreed on smaller extensions with both Tim Byrdak and R.A. Dickey.