How close was free-agent first baseman Paul Konerko to signing with the Diamondbacks?

Closer than you might think.

Both Konerko’s agent, Craig Landis, and White Sox officials say the turning point in the negotiations occurred Tuesday night when the team agreed to guarantee Konerko a third year.

Before that, the White Sox had been offering two years and a club option. The Diamondbacks’ first offer was three years, $30 million.

Konerko planned to visit the Diamondbacks next week to escalate negotiations if the White Sox didn't improve their proposal, according to a source with knowledge of the discussions.

“He was very tempted,” Landis said. “(The D-Backs) clearly were his second choice. We had already made up our mind that if things broke down with the White Sox, the next thing we were going to do was get more serious and engage the Diamondbacks to accomplish a three-year deal for Paul in Arizona.”

The White Sox ultimately signed Konerko to a three-year, $37.5 million contract with heavy deferrals in the third year. He'll earn $12 million in both 2011 and ’12, $6.5 million in ’13 and $1 million per year from ’14 to ’20.

The Rangers were Konerko’s third choice – no offer was made, but the two sides discussed the parameters of a deal, Landis said. The Orioles showed interest, but were never a serious contender.

-Ken Rosenthal