Northamptonshire have confirmed the return of Australia spinner Ashton Agar for their vitality Blast quarter-final against Somerset.Agar was signed as a replacement for Sikandar Raza during the group stage, joining after the T20 World Cup and helping Northants to four wins out of five as they qualified from the North Group in second spot.The club are also working to try and bring back Matthew Breetzke, the South Africa opener who is currently Northants’ leading run-scorer in this year’s Blast, with 460 at a strike rate of 153.84 – although head coach, John Sadler, said the decision was in the hands of Cricket South Africa.Breetzke was recently involved on South Africa’s Test tour of West Indies but is not part of the squad currently playing a three-match T20I series.”We’re hopeful that Matt will be able to get over but we’re not sure how that’s going to pan out,” Sadler said. “We obviously want to get him back because he’s been brilliant for us but we’ll see how it unfolds.”It’s a situation that is out of our and Matt’s hands to be honest. I know he’s desperate to come back but he’s on the verge of playing for South Africa in all three formats so that’s understandably his main driver.”I also know that he so wants to come back and play for us that he’s happy to fly in, play and fly back out but that is a situation that we’ll have to negotiate with Cricket South Africa.”Agar, who opted to go freelance earlier this year, will be available after completing a stint at the Global T20 Canada, and strengthens Northants’ options ahead of a soldout game at Wantage Road against the defending champions on September 5.”Ashton is in, he’s booked to come back and he’s incredibly excited,” Sadler said. “He has been over at a tournament in Canada so he’s off back home to spend some time with his family but then he’ll be back with us so we’re absolutely delighted with that.”