Imps manager Peter Jackson has revealed that his former Huddersfield striker John McAliskey has not done enough to earn a shot at an Imps contract.
Jackson told BBC Radio Lincolnshire: "My main aim was to look at McAliskey but that didn't really work out, I won't be taking that any further."
However he revealed that striker Calliste and defender Swaibu had done enough to keep him interested after playing in the Imps reserves' 3-1 win over Port Vale.
"Maybe we'll look at the other two another time, I thought they did well."
McAliskey played under Jackson at Huddersfield before linking up with Mansfield last season. He did score in the reserves game, but didn't perform well enough to warrant a second look.
Former Wales Under-21 international Calliste began his career at Manchester United before moving to Liverpool but failed to make the grade. He found himself at Scunthorpe Utd, but broke his ankle in a friendly game and didn't make a senior appearance for The Iron.
This season he has been playing for Cambridge City in the Southern Premier Division, but left in pursuit of League football. He recently had a trial at big spending Shrewsbury.
Central defender Swaibu, 19, has been playing for Bromley in the Blue Square South following his release by Crystal Palace in the summer.