Definitely. The main reason why he left Liverpool was because the opportunity of game time was slim (they wanted him to stay and had offered him a better termed deal to stay). Press reports indicate that Sinclair is eager to leave Watford on loan and get first team experience as he's not happy...
If it is Sinclair and he has a choice between the two clubs then the decision he makes will say a lot about his temperament and ambition. Cardiff are extreme light on strikers at the moment and chances of walking into the team straight away there are high, whereas here any striker that arrives...