I’m not sure when it began—maybe the picture I saw was the very first—but I saw visual evidence of cement being poured in the Chicago Cubs’ off-season bleacher reconstruction project on Monday. After weeks of striking pictures of the stadium’s long-time horizon line being demolished, and a fair few pictures where nothing seemed to be happening, and nothing was left, Monday was the first concrete reminder that there will be bleachers there again, and soon, at least for me. I bring this up because Monday morning was also the time that the Cubs’ on-field reconstruction took on a sense of concrete progress. The team agreed (this remains unofficial, but has been independently confirmed by so many trustworthy reporters that I feel confident passing it along) to sign Jason Hammel to a two-year, $18-million contract, with a $12-million team option and $2-million buyout clause covering the 2017 season. Hammel, the astute reader recalls, signed a one-year deal for $6 million last winter, also with the Cubs, and the team traded him on Independence Day.

Hammel isn’t a star. He isn’t a savior. To return to the renovation as a metaphor, Hammel is not a video board going up in left field, nor widened walkways or extra revenue-generating signage. He’s a piece of the foundation. Many potentially good teams succumb to a dearth of guys like Jason Hammel, who can take the mound 25-30 times and keep you in the thing after six innings, and fall out of contention. Depth is a pitching staff’s most important virtue, and the 2015 Chicago Cubs weren’t going to have enough depth without signing someone of Hammel’s ilk.

Hammel’s ilk, by the way, is the league-average starter. He’s never going to be much more, and he’s never going to be much less. The variable is health, and Hammel, while no workhorse, survives. He threw a great mix of pitches while with Chicago in 2014, becoming (though it’s a cliché) a sinker-slider guy. He threw more sinkers and fewer four-seam fastballs, more sliders and fewer curveballs. It worked like a charm, and he even did the one thing he had never done all that well—he struck some people out. Once he lost the daily tutelage of Cubs pitching coach Chris Bosio, Hammel reverted to some old habits in terms of pitch selection and approach within at-bats, and his numbers turned ugly for the star-crossed Oakland Athletics. There’s cause to believe he might get some of his groove back now that Bosio will be at his elbow again, and even after regressing the star-caliber work Hammel turned in that half-season, that’s an appealing possibility.

If Chicago is serious about contending next season, though, Hammel can be only the first step. This contract isn’t necessarily from the flippable-asset family tree, the way last year’s was. While most people agree that this is a good deal, and I don’t mean to suggest that the Cubs erred by taking the opportunity to capture value, this move is just concrete taking up space in the dirt, unless the front office builds upon it. Thankfully for Cubs fans, though, the front office is as aware of that as anyone.

At the other end of the day Monday, the sketches of what that group intends to build on the foundation Hammel helps strengthen began to come into focus. First, there was this:

#Cubs, #DBacks discussing trade that would send Miguel Montero to Chicago, sources tell @Ken_Rosenthal and me. @FOXSports

— Jon Morosi (@jonmorosi) December 9, 2014

Than came this:

If #Cubs get Lester, industry source says next move would be to pursue big bat and try to accelerate revival. A bat in addition to Montero.

— Ken Rosenthal (@Ken_Rosenthal) December 9, 2014

Obviously, nothing has come to fruition yet. I’m writing as Monday becomes Tuesday in the Central time zone, and as far as I know, Jon Lester is still a free agent, and Miguel Montero is still an Arizona Diamondback. Still, it looks like the Cubs intend to build quickly, and that each possible addition they make invites serious speculation about another. Hammel was groundwork. He was a start. If the team is going to take a real and meaningful step forward in 2015, they’re going to do it by making him the 11th-most famous player on the team between now and Opening Day. Tuesday will bring some answers about whether they can do that. We probably won’t see the whole picture until at least April, though. Coincidentally, that’s also when the team will play its next game at the renovated, bleacher-expanded Wrigley Field.