League Two side Cambridge have signed Gillingham striker Ben Williamson and Sheffield United defender Terry Kennedy on loan until 3 January.
Ex-Port Vale forward Williamson, 26, has failed to score in 14 appearances since joining the Gills in the summer.
Centre-back Kennedy, 22, has made 24 appearances for the Blades since coming through the club's youth system.
The pair are Shaun Derry's first signings since he became U's manager last week.
"Both players will have to fight for the right to play, but the fact they bring additional competition to the group should increase the intensity of the squad," said Derry.
"Terry is a very commanding central defender which will put extra pressure on what we already have in that position. Like every player he will have to earn his place in the side, but the competition will certainly be fierce.
"In terms of Ben's performances, I hope he can reproduce the form that we saw during his time with Port Vale. If he is able to strike up a similar relationship with the players we have here, then I'm sure he will do well for us."
Meanwhile, defender Alie Sesay has returned to Leicester City following the expiration of his loan deal.