The Buffalo Bills have added a pair of assistant coaches - reportedly, not officially - to go along with the defensive additions announced earlier this week. While the first round of hires focused on the defensive side of the ball, the offensive side waited until after the hiring of Greg Roman, and some shake-ups in other organizations.

Per source, former Chicago Bears OC Aaron Kromer will join the Buffalo Bills staff as offensive line coach http://t.co/sNnVtz3C1h — FootballScoop Staff (@FootballScoop) January 17, 2015

By the way, the #Bills QB coach will be David Lee, most recently of the #Jets under Rex Ryan. — Ian Rapoport (@RapSheet) January 17, 2015

Lee is a name that should be familiar to Bills fans. He spent one year tutoring Ryan Fitzpatrick and company in Chan Gailey's final season in Buffalo before spending the past two years with the Jets and Rex Ryan's staff. He was also the Dolphins' quarterbacks coach from 2008 to 2010 under Tony Sparano.

Kromer is a strong add for the Bills' much-maligned offensive line. He coached the New Orleans Saints offensive line from 2009 to 2012 (where he took over for the one and only Doug Marrone) before spending the past two seasons as the Chicago Bears' offensive coordinator. When Sean Payton was suspended in the Gregg Williams scandal, Kromer served as the team's interim head coach with Joe Vitt. He's also been in charge of the offensive line for the Tampa Bay Buccaneers (2006-2007) and Oakland Raiders (2001-2004).

Here is the full list of coaches so far (note that coaches marked with an asterisk have not been confirmed by the team):

Rex Ryan | head coach

| head coach Greg Roman | offensive coordinator

| offensive coordinator Dennis Thurman | defensive coordinator

| defensive coordinator Danny Crossman | special teams coordinator

| special teams coordinator David Lee* | quarterbacks

| quarterbacks Aaron Kromer* | offensive line

| offensive line Tony Sparano, Jr. | tight ends

| tight ends Karl Dunbar | defensive line

| defensive line Jeff Weeks | assistant defensive line

| assistant defensive line Bobby April III | linebackers

| linebackers Jason Rebrovich* | outside linebackers

| outside linebackers Donnie Henderson | co-defensive backs

| co-defensive backs Tim McDonald | co-defensive backs

| co-defensive backs Eric Smith | special teams assistant

| special teams assistant Eric Ciano* | strength and conditioning coach

| strength and conditioning coach Jason Oszvart | strength and conditioning assistant