Based on the cbssports mocks, and some others, I combined them to get a guess who would be available & gone at #21. Based on that, these folks are gone by #21:
CB - D Milliner
DE - B Werner, D Moore, E Ansah
DT – S Lotulelei, S Richardson, J Hankins
ILB - M T’eo
OLB - J Jones, B Mingo
OL - L Joeckel, C Warmack, E Fisher
QB - G Smith, T Wilson, M Glennon
TE - Z Ertz
WR - K Allen, C Patterson
So here goes....
1.21 Jonathan Banks CB
Thorpe winner could be a shutdown corner. Paired with Hall at CB, sliding Dre to S with Nelson could give Cincy a great secondary to fix the problems they have had with good QB’s the last few years. Instead of reaching for a Safety at 21, I’m taking a very good CB, and moving a CB to S.
2.05 Jonathan Cooper, G/C
No, I didn’t mis-spell "Giovani Bernard". Usually in round 2, the Bengals start taking the BPA, which could be Cooper. Cook is stop-gap, and Stephens looked overmatched at times. Cooper could be an upgrade over both, giving the Bengals a young, solid interior of Zeitler-Cooper-Boling.
2.21 Arthur Brown, ILB
Good player who can help bolster the LB corps. Could keep Burfict outside, where he did so well for us?
3.22 Tank Carridine, DE
Knee injury knocks him down. Could be a good value once he recovers. Gives a little depth to rotate with Dunlap & the re-signed MJ93.
4.21 Marcus Lattimore RB
We likely don’t get much from him in 2013. But we didn’t get much from Dre either. Could have been the top RB in the draft if not for the injury. Could be a very good value to be had here.
Later on, I’d also take a QB to be a backup to Dalton and Tyron Mathieu S
I didn’t take a RB to step in immediately, but they signed BJGE to a multi-year deal. Also, Peerman looked good in his limited play. I’d like to see Peerman get more of a chance to split w/BJGE, who isn’t going anywhere.
I didn’t take a WR, but Sanu & Jones looked like decent options opposite Green. Hawkins still has a role too.
Just like every other mock, it's imperfect, it was done without 3 days of massive study, and it's a guess.