The 17-year-old striker has signed a one-month loan deal from QPR and will go straight into Waddock's squad at Edgar Street.
German has made three substitute appearances for Rangers - most recently on the final day of last season - and will hope to be gain much-needed first-team experience at the Rec.
Waddock said: "He has first team experience and this is a great opportunity for him.
"We can help to further his development and he can help us out too."
Waddock saw his side beaten in Chris Sutton's first game in charge of Lincoln at the weekend but will be looking to get back to winning ways.
Captain Adam Hinshelwood is now fit after a knee injury while midfielder John Halls also has a chance of returning from the groin problem which has kept him out of the last three matches.
However, defenders Dean Howell (hip) and Andy Sandell (ankle) are out while midfielder Ben Harding (ankle) completes Waddock's injury list.