To be honest, I feel that we don't need a right back and certainly don't need a centre half. I know we only have one proven right back in Raven but Shinnie was perfectly capable of filling in at right back in Raven's absence. I know you could argue that Shinnie being at right back did run it's course after a while but also not forgetting Josh Meekings started at ICT as a right back so you could place him there too. I could understand if Yogi is looking for established right back to challenge Raven but I feel we are well covered unless Shinnie was leaving ICT.
Same case for a centre half. Gary Warren and Josh Meekings first team starters - no question about it. We have a perfectly capable replacement in Danny Devine. Graeme Shinnie's versatile enough to fill in at centre half and so is Carl Tremarco. We also have Jason Brown in the U20s that can fill in at centre half too. So again, yogi could be looking for a bit more competition but I wouldn't be sad if we didn't get one.
To me a second striker should and probably is our main priority. We can get so much benefits out of having a second striker if we played a 4-4-2 and kept the opposition on their toes because they would be expecting us to play the usual 4-2-3-1. I do feel that we need this second striker incase Mckay gets injured or suspended however you could counter that by how many goals have come from midfield/defence when Mckay was off the boil. We have Calum Ferguson at our disposal already but I think he should be kept for the future and let him keep developing in the U20 and possibly another loan spell at either the Championship or League 1. As Yogi pointed out in an interview in May you're stuck between a rock and a hard place when you get a second striker because they will be expecting to play week in week out but as I said if we altered the tactics then it shouldn't be a problem.