Major league clubs are three weeks into spring training, and the weaknesses on big league rosters are becoming apparent. Inevitably, trades will go down before Opening Day, intended to fill holes. Most March deals provide teams more depth coming off the bench, but sometimes they give a team a new piece in the starting lineup or rotation.

A number of possible regulars and starting pitchers could be dealt this month. Most of them have been front and center in offseason rumors, and not much has changed. A few may be wearing new uniforms on Opening Day.

The rebuilding Baltimore Orioles may still provide a new address for second baseman Brian Roberts. The Cubs have rarely had a leadoff hitter with a decent OBP in my lifetime, and Roberts could provide that. Chicago is the most frequently suggested destination, but maybe the cross-town White Sox would be a good long-term fit.

The White Sox have two third basemen, including prospect Josh Fields, who slugged 23 homers in 100 games after Joe Crede went down with a back injury. Crede is in camp after rehabbing his way back, and the early word is that he seems fully recovered. It has been reported that the 29-year-old veteran has drawn the interest of the San Francisco Giants, but any suitor will want to know with more certainty that Crede is healthy and ready. Maybe Cleveland could use an upgrade, though a deal within the AL Central Division seems unlikely.

Top Red Sox prospect Jacoby Ellsbury has all but put Coco Crisp out of a job with a strong showing in September and the postseason. Crisp, who is a terrific defender in center field, has been a disappointment at the plate since joining Boston in 2006. Crisp has discussed asking for a trade, and his wish may be granted. A number of teams could use an upgrade in center. The Cubs, with aspirations to end 100 years of futility, could use him and give Felix Pie more development time. Reportedly Oakland is very interested in acquiring Crisp, but Boston isn't going to give him away.

The Athletics also are in rebuilding mode, and Joe Blanton’s name has circulated in trade rumors all winter long. The anticipated contenders who could use him near the back of their rotation are too numerous to count, and he should bring a nice return in trade. Blanton is coming off a solid season, and it would seem his trade value is as high as ever. It could be even higher at the trade deadline if he builds on his 2007 success, though there’s some risk in taking that chance. If Blanton stays, he most likely will be Oakland’s Opening Day starter.

The Detroit Tigers have replaced Brandon Inge with slugger Miguel Cabrera, and Inge would be reduced to a utility role if he stays in Detroit. That's a role he seems ideally suited, but the third baseman has asked for a trade because he wants to start. Getting a regular gig at third isn't assured no matter where he goes. A team looking for a regular third baseman probably would be more interested in Crede, though Inge would have a lower price tag on the trade market.