DENVER -- The Rockies and free-agent first baseman Justin Morneau continued work Wednesday toward what is likely to be a two-year, $12.5 million contract with a mutual 2016 option, but it's unlikely there will be an announcement until next week.

The sides are still discussing terms, then Morneau, 32, must pass a physical. With athletic trainers and medical personnel due in Lake Buena Vista, Fla., this week -- a few days ahead of the Winter Meetings, which start Monday -- the physical probably won't take place immediately.

Once the deal is completed, the Rockies will have a right-left complement at first base, with Morneau starting against right-handed pitching and catcher Wilin Rosario moving to first against lefties. It also could give manager Walt Weiss a more versatile lineup. The Rockies need firepower and versatility after seeing their offense desert them too often during a 74-88 finish that left them in the National League West basement.

If Morneau, who broke in with the Twins in 2003 and was there until joining the Pirates for their stretch run last season, upholds his career performance against right-handed pitching, and Rosario (49 home runs the last two seasons) becomes competent at first base, the Rockies could make progress with two vexing issues.

Rosario played 117 games in 2012 and 121 in 2013. The platoon plan could give him about 100 extra at-bats (he had 449 last season), with many of the additional chances against left-handers (.323 average, seven homers, 29 RBIs in 56 games last year). The plan would give switch-hitting Jordan Pacheco more opportunities at catcher. Pacheco's numbers took a hit last year because of irregular playing time, but in 2012, when he saw regular duty at third base and first base, Pacheco hit .351 with a .394 on-base percentage against lefty pitching.

Also, Morneau has a .292 career batting average and .893 OPS (on-base percentage plus slugging percentage) against right-handed pitching. Last year, after battling injuries from 2010 to 2012, he posted a .280 average and .819 OPS against righties.

Not only could Morneau be an asset in the starting lineup against righties at Coors Field, but on days he does not start he could give the Rockies a left-handed power bat off the bench. That could be useful on what figures to be a bench full of youth but with little proven ability late in games.

It would give the Rockies a weapon against some of the power closers in the National League West, such as the Giants' Sergio Romo and the Dodgers' Kenley Jansen. Morneau, the 2006 American League Most Valuable Player and a four-time All-Star, doesn't have much experience pinch-hitting but has strong numbers -- 9-for-28 (.321) with three home runs and 10 RBIs.

The plan is contingent on both Morneau and Rosario being healthy, meaning Morneau showing that the 152 games he played last year was not an aberration and Rosario handling the wear and tear of regular catching duty.