Should the Royals sign Danny Duffy to a contract extension?

Danny Duffy has emerged as the best Royals starting pitcher here in mid-June, an unexpected development considering he did not even make the rotation when the season began. Since re-joining the rotation back on May 15, Duffy has a 3.33 ERA with 10.7 strikeouts-per-nine innings.

The results shouldn't be that surprising. Duffy has been a very solid starting pitcher since returning from Tommy John surgery in 2013. From 2013-2016, Duffy has posted a 3.29 ERA (although a 4.19 FIP) with 7.2 strikeouts-per-nine innings as a starting pitcher. The problem is that he has averaged just 5.4 innings per start over that time, walking 3.3 hitters-per-nine innings. This year, Duffy has lowered that to 2.0 walks-per-nine innings as a starter, and has gone six innings or more in four of his last six starts, including a career-high eight-inning performance on Monday against St. Louis.

The Duffy resurgence coupled with the disappointing performance from the rest of the starting rotation has caused some to wonder if the Royals should commit to Danny Duffy long-term. The left-hander is a free agent after the 2017 season. He once tweeted "Bury me a Royal" upon signing a contract with the Royals, and his affinity for the organization that drafted him and stuck with him even after he temporarily left the game of baseball and suffered through career-threatening Tommy John surgery is well noted. Does the feeling of loyalty go both ways?

Shaun Newkirk looked at what it might take to sign Duffy before last season, but events have changed since then, and Duffy is a year and a half closer to free agency. On 610 Sports, Danny Parkins and Carrington Harrison discussed the matter with Yahoo! Sports writer Jeff Passan, with "The Drive" hosts throwing out a number of five years, $60 million for Duffy. Passan disagreed.

"If Danny Duffy were a free agent right now, I don't think he would get $50 million guaranteed....There is absolutely no chance in hell the Royals will do that.....I think if you offered him $40 million over five years he would take it.....If you are the Royals right now and you want to offer Duffy a contract extension, its five years, $25 million and you see what he says."

Duffy is signed to a $4.225 million deal for this year, and will enter his final year of arbitration in 2017 before being eligible for free agency after the season. Depending on his performance this year, he can expect to make $6-8 million in arbitration next year.

What should he expect to make in free agency?  Duffy has shown flashes of brilliance, but the big mark against him has been innings pitched per start. Duffy only lasts 5.34 innings-per-start, a problematic number for many teams without a bullpen as deep as the Royals. How have other free agents with similar issues going deep in games fared in free agency?

Jason Hammel is having a career year with the Cubs, but he has been an up-and-down pitcher most of his career. He averaged just 5.72 innings per start prior to signing a two-year $18 million deal with the Cubs with a $12 million club option (and $2 million buyout) before the 2015 season.

Old friend Jorge de la Rosa found success upon leaving the Royals, pitching in the thin air of Colorado. But he has always struggled with his command, much like Duffy, and has trouble going deep in games. That didn't stop the pitching-starved Rockies from signing him to a two-year contract extension for $19.5 million plus a $11 million player option before the 2011 season.

Current Royals starter Edinson Volquez had an inconsistent track record when the Royals signed him before the 2015 season. Up to that point he had a higher walk rate in his career than Duffy has now, and only averaged 5.6 innings per start in his career. That did not deter the Royals from offering him a two-year $17 million deal with a mutual option for $10 million with a $3 million buyout.

The Royals had originally wanted Francisco Liriano, who had a similar shaky track record with an injury past. The signed a "make good" one-year contract with an option with the Pirates. But after proving himself there, they signed him to a three-year, $36 million deal before the 2015 season, and has stayed healthy.

J.A. Happ surprised many by landing a three year, $36 million contract with the Blue Jays, despite some underwhelming numbers in his career. The left-hander only averaged 5.67 innings per start in his career, with numbers very similar to Danny Duffy.

Here are the career numbers of these starting pitchers at the time they signed their multi-year deal, compared to Duffy's as of right now.

It seems that Duffy can probably expect around $10-12 million per year as a free agent if he keeps up his numbers, but he probably should not expect more than a three-year deal on the open market. Combined with his last remaining year under club control, that means an extension would be a four-year deal, worth around $36-44 million.

Duffy is still a big injury risk as a Tommy John survivor, but at that amount, a career-threatening injury would not be devastating to the Royals. The team would also have a fallback option sending Duffy to the bullpen if starting does not work out. As a reliever, Duffy would be earning higher than market value, so perhaps the contract could be structured to a lower base salary with incentives built in for games started.

Danny Duffy seems to love pitching in Kansas City, and his energy and enthusiasm can be quite infectious. But the Royals need to make a decision based on what works best for the club. The fact they need starting pitching so badly may require them to overpay to keep a talent like Danny Duffy. As the only starting pitcher Dayton Moore drafted that has turned into a serviceable starting pitcher, the Royals may want to hang onto the talented arm if the price is right.