The mythical book general manager Jack Zduriencik has written on "How to Build a Winning Team" includes a reference to the importance of having a strong defense up the middle.
"You must have a shortstop capable of catching baseballs hit up the middle," he said. "That's why it was so important for us to re-sign [Jack] Wilson."
The Mariners are being built around pitching and defense in 2010, and coaxing Wilson back with a revamped two-year contract gives Seattle one of the premier defensive shortstops in the Major Leagues.
The Mariners exercised the $600,00 buyout that was included in the four-year contract Wilson signed with the Pirates, and instead of paying $8.4 million in 2010, worked out a two-year, $10 million deal.
So when the regular season begins on April 5 against the Athletics in Oakland, Wilson will be stationed at shortstop and, looking to his left, he most likely will see Jose Lopez at second base. There have been some internal discussions about seeing what the defense would look like if Lopez played third base and Chone Figgins played second, but it hasn't advanced past the talking stage.
Even so, don't be surprised if that alignment shows up during Spring Training a time or two.
For the most part, however, it appears the double-play combination in 2010 will be Wilson and Lopez. They were the keystone combination for most of August and the first two weeks of September last season, but they are still relatively new DP partners.
Speaking of new, the Mariners have a new infield coach in Mike Brumley, who played for Seattle in 1990 and most recently has been a coach/manager in the Angels' Minor League system.
"I don't know much about [Wilson and Lopez], other than what I have seen on TV," Brumley said.
Injuries to Wilson's left hamstring and right heel prevented Mariners fans from seeing the highlight-reel caliber of play he became known for during his eight-year career with the Pirates.
"I am 100 percent healthy and really, really excited to be back in Seattle," Wilson said. "It's such a great chance to win and compete. I want to show [the fans] who I really am and what I can do."
Best known for his glove -- Wilson has twice played at least 50 consecutive error-free games -- Wilson's offensive resume includes a .308 batting average in 2004, when he was selected to the National League All-Star team, and a .296 mark in '07.
It is safe to say the .224 average he compiled in the 31 games he played for the Mariners last season was not the real Wilson, and with better health and more knowledge of American League pitchers, there could be at least a 50-point improvement.
Lopez, still only 26, has become one of the best offensive second basemen in the big leagues, improving in each of the past four seasons in home runs (10, 11, 17, 25) and driving in a career-best 96 runs last season after an 89-RBI campaign in 2008.
In other words, he hits like a third baseman.
But for whatever reason, Lopez's defense has gone a little south.
"There are some things I would like to try with him to improve his range," Brumley said. "I want to check out his conditioning program to make sure he's in good shape and work on his flexibility -- things like that."
Having a left-handed first baseman like Casey Kotchman would reduce some of the pressure on Lopez to snag ground balls to his left, but it isn't much the hard-hit grounders that scoot through the right side that concern Brumley the most. It's those little pop flies that fall into shallow right field that drive him nuts.
"Those are the hits that move runners from first to third, or second to home," he said, adding that positioning also would be stressed during Spring Training and beyond.
The same goes for the backup middle infielders, including Matt Tuiasosopo, Dustin Ackley and non-roster invitees Josh Wilson and Chris Woodward.
"We're going to work hard in camp, I can promise you that," Brumley said.
There could be two backup infielders on the eventual 25-man Opening Day roster, and Ackley, the No. 2 selection overall in last year's First-Year Player Draft, will get some playing time during the early stages of the Cactus League schedule to get a better reading on his progress as a second baseman.
A shortstop in high school, Ackley played center field during his first two seasons at the University of North Carolina before moving to first base following Tommy John reconstruction surgery on his right elbow.
Tuiasosopo was the big story of the camp last season, batting over .400 and earning a spot on the Opening Day roster.
"Tui has to take care of his own business," manager Don Wakamatsu said. "He did that last year. He has gotten quicker and stronger and he needs to keep doing that, regardless.
"He will get a chance to play in Spring Training and show us what he can do. I like Tui. He is a tremendous teammate and has talent. He just needs to prove that he can play at the Major League level."
Jim Street is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.