If you thought choosing the Diamonds' midcourt is going to be tough, there are some pretty big headaches waiting at either end of the court for selectors when they sit down to pick their team for the end of year internationals.

The big question marks are in relation to two key positions – goal attack and goal defence – and it is where selectors are likely to keep a close eye in this week's final round and the finals series starting the following weekend.

First to the easy decisions.

The goal shooters have picked themselves, with both the Caitlins – Thwaites and Bassett – streets ahead of anyone else. On one hand this is terrific, in that there are two of the world's best goalers ready to bib up for the Diamonds. On the downside it is alarming that there are no heirs apparent trying to push them out. The statistics bear this out. Thwaites and Bassett have scored 555 and 550 goals respectively this season. They are the most prolific goal shooters by a long shot. The next best Australian in that position is West Coast Fever's Kaylia Stanton who, with 271 goals, has scored less than half of the Diamonds incumbents. This is a huge issue that no doubt has Diamonds coach Lisa Alexander concerned.

Sharni Layton is the only walk-up starter in the defensive line. She has been outstanding this year, leading the way for intercepts, with 50, and sitting second for deflections and third for defensive rebounds. She is a ball winner and crucially, a game winner.

The big question is of, course, who will partner her. While Layton can play goal defence and wing defence, she is fast becoming a specialist goal keeper, and it is unlikely she will be pushed forward for the international season without the match-fitness that can only be acquired from spending lots of time in goal defence. As a result Diamonds selectors will likely look at picking an understudy goal keeper and two goal defenders.

Giant Bec Bulley and Vixen Jo Weston are the two best goal defenders in the league this season and should be selected, although Bulley has yet to decide if she wants to extend her comeback to international representation. If she doesn't, then it is an open field as to who gets the nod. Statistically it is the Queensland Firebirds' Kate Shimmin who is putting up her hand. She is the best-placed Australian defender for possession gains, and has had a pretty strong season.

In terms of an understudy goal keeper the field is wide open, with some great young talent demanding attention. Emily Mannix has been super impressive for the Vixens this year, and has to be in the frame. Having said that, Giants' Sam Poolman and Swifts' Sarah Klau have been revelations this season, and with Fever's Courtney Bruce the incumbent understudy its anyone's guess who will get the nod, although my money is on Mannix.

Which brings me to the linchpin position of goal attack. The intrigue is that two of the best in that position this year have been Vixens' Tegan Philip and Lightning's young gun Steph Wood. Philip has scored the most goals of any goal attack in Suncorp Super Netball this season, and Wood, despite missing early matches with knee soreness, has established a solid combination with first-choice Diamonds shooter Bassett.  Neither of these two toured with the Diamonds this year, but it is likely that both will be in the selection frame.

The question is which one. Incumbent goal attack, Fever's Nat Medhurst, has had a season she would rather forget, but her class has sat just below the surface all year, and she would still have to be one of the first selected. I suspect Philip may just get the nod, depending on her finals form.

Having said all of that, there is a high likelihood that with seven Tests over two series, selectors will opt for a couple of teams to give players every opportunity to prove themselves before the Commonwealth Games. It will be survival of the fittest and will make for fascinating viewing.