"That's kind of what happened," Konz said in a telephone interview. "It was a surprise, but it was a great surprise."
Atlanta made Konz (6-5, 314) the 55th overall pick and the team's first selection.
Holmes (6-5, 323) played two years at Southern Miss and was a first-team All-Conference USA selection by the league's coaches in 2011. He transferred to Southern Miss from Itawamba Community College.
General manager Thomas Dimitroff said the Falcons, who didn't have a first-round pick, placed an emphasis on adding bulk with the two picks.
"We talked about that," Dimitroff said. "We talked about coming in here and getting some wide loads and quite honestly Lamar is a double-wide load. He's a big man who has a presence as far as his stature and such."
The Falcons moved down seven spots in the third round in a trade with Baltimore. Atlanta added the 29th pick of the fifth round, No. 164 overall, in the trade.
The trade leaves the team with four picks on Saturday, two in the fifth round, one in the sixth and one in the seventh.
"He's going to be a guy who can play both positions," Smith said. "As you know when you have seven (offensive linemen) active on game day, you've got to have guys who can play multiple positions."
Added Dimitroff of Konz: "We hope he can come in and compete for a starting job."
Smith said the rookies will be part of a renewed competition for starting jobs in the offseason.
"We're going to have an open competition," Smith said. "I think competition brings out the best in everyone and these two guys that we added, we're going to put them right in the mix. We'll have a very competitive offseason and it'll start with the rookie minicamp in two weeks."
Konz said he played only center at Wisconsin, while starting 31 of his 32 games, but also practiced at tackle and guard.
If he plays center, Konz could be an eventual replacement for Todd McClure, who is 35 and entering his 14th season. Joe Hawley moved from guard to start three games center last season when McClure was injured.
Konz said he had not been told what position he will play in Atlanta.
"I'll do anything," Konz said. "At Wisconsin they made sure I knew tackle, guard and center. Anywhere I can help the team, that's my responsibility."
Konz was projected as a possible first-round pick.
"Just getting the opportunity is amazing," Konz said. "It doesn't matter where I fell to because I love the team that picked me. I have nothing but great respect for the organization. Now I get to help be part of a winning tradition."