When the San Francisco 49ers defense came onto the field to start the second half on Monday night in St Louis their offense had just spotted them to a three point lead. There was only one small problem. Three All-Pro linebackers were missing. Aldon Smith and Navorro Bowman have been missing all season, but now Patrick Willis was out too. This brought rookie Chris Borland onto the field for his first meaningful defensive snaps.

The 49ers defense responded by forcing the Rams to go three and out.

In the process rookie Jimmie Ward was lost for the night to a quad injury forcing Chris Cook into the lineup at left cornerback and moving Perrish Cox into the slot.

No problem. The 49ers defense gave up a first down, but that was it. In the second half without their All-Pro linebackers and starting slot cornerback the 49ers defense held the Rams to 98 yards on 37 plays, and rookie Dontae Johnson put the game away when he returned an interception for a touchdown.

It was a tremendous job by Vic Fangio and his defensive staff to shut down the Rams while juggling an ever changing roster.

It also put a spotlight on the work that Trent Baalke and his scouting staff have done since taking over for Scot McGloughan in March of 2010.

There is still a faction of the 49ers fan base that gives McGloughan more credit for where the 49ers are today than Baalke but make no mistake, these 49ers are definitely Baalke's creation. Only eight players on the current roster were brought in before Baalke took over.

Baalke's detractor's will point to his draft day misses. The 2012 draft in particular stands out. What's interesting about that draft is while only Joe Looney remains with the 49ers, five of the other six players are still on NFL rosters.

The draft is only one part of an NFL general managers job responsibilities and focusing only on that area is a bit myopic. In addition to the draft they need to manage the selection of undrafted free agents, bringing in free agents from other teams, and who they want to retain among their own free agents.

This is the part of the job where Baalke has excelled. Ian Williams, Michael Wilhoite, and Tramaine Brock are all undrafted free agents who have earned starting roles, while Tony Jerod-Eddie, Demarcus Dobbs, L.J. McCray and Dillon Farrell have also earned positions on the current 53-man roster.

Baalke has used free agency to bring in Antoine Bethea, Dan Skuta, Perrish Cox, Craig Dahl, Chris Cook, Brandon Lloyd, Phil Dawson, Kyle Nelson and Kassim Osgood. All players who fill key rolls on the active game day roster.

One of the biggest knocks against Baalke has been his lack of success with acquiring wide receivers through the draft. A.J. Jenkins was the poster child for draft mistakes. There was even a whiff in free agency when he brought in Braylon Edwards in 2011. Those mistakes have been made up for with trades the last two offseasons for Anquan Boldin and Stevie Johnson.

A strong argument can be made that the 49ers have the best 1-5 receiving corps in the NFL.

Beating up on the St Louis Rams and a quarterback making his fourth career start is one thing. Doing it against the defending AFC Champions who have a future hall of fame quarterback on the road is a much more daunting task.

If the 49ers are able to defeat the Broncos on Sunday night it should put an end to the debate, and they should just hand Baalke the executive of the year award on the spot.