Russell Martin is believed to be seeking a deal for about five years. (Getty)

The Cubs, already the leader in free agency after landing marquee manager Joe Maddon for a $25 million, five-year deal, are going to target top free-agent catcher Russell Martin, sources connected to the team said.

The Cubs, expected to be a big player in the market with hopes of contending as they blend in their impressive stash of top positional prospects, surely appreciate Martin's superb performance for the Pirates this past year, when he was one of the few players in baseball with a .400-plus on-base percentage, and also caught and threw with the best in the game behind the plate.

The Cubs are expected to target one of the top free-agent starting pitchers, with Jon Lester and Max Scherzer seeming to make more sense for them than James Shields due to their younger ages, and could also look to enhance other areas, possibly the bullpen. Left-handed reliever Andrew Miller, who should be popular this winter with many teams, would make sense, as well.

The Dodgers, Martin's first team, are expected to be a player for the catcher, whose market should be terrific following his great performance in his walk year -- though the Pirates will do what they can to try to prevent him from walking. Yes, the small-market incumbent Pirates indeed do seem intent on giving it their best shot.

Pittsburgh, which extended the $15.3 million qualifying offer that he will surely turn down, is said to be quite interested in bringing back Martin to the point of going to unusual lengths for them to try to make it happen. The Pirates, as was reported here, made a multiyear proposal during this his walk season, and while such a late try was a long-shot, it is believed to have been a serious effort on their part.

The Blue Jays are said to have interest in Martin, as Jeff Blair of Sportsnet.ca in Canada reported, and the Red Sox have been viewed as a possibility, though it is also possible they could go with youngster Christian Vazquez. Martin originally hails from Montreal, so he may appeal to the Jays for that reason, though Dioner Navarro didn't do a bad job for them last year and they have other needs (second base or third base, bullpen).

Martin is believed seeking a five-year deal considering that has been the precedent set for top catchers. Brian McCann, Yadier Molina and Miguel Montero all signed five-year deals, for $85 million, $75 million and $60 million, respectively. It should be noted that the Molina and Montero deals were done before free agency, and Molina's was done before he became commonly viewed as a superstar.

Martin hit .290 with 11 home runs and 67 RBI after dedicating himself in the offseason to improving his contact hitting. He was also one of four players with 400 plate appearances to post that .400-plus on-base percentage, with his .402 mark joining teammate Andrew McCutchen (.410), Victor Martinez (.409) and Jose Bautista (.403) at that magic figure. The high on-base mark has to appeal to analytics experts such as Cubs higher-ups, including Maddon.

Martin also ranked near the top among catchers by gunning down 39 percent of baserunners and is known as a good pitch caller and framer. He makes sense as a fit for the Cubs, with the issue being the competition for his services.