Kellock led Scotland to a 2-0 series win over the Pumas in 2010, but he has lost his place in the team to Richie Gray and Jim Hamilton - with Nathan Hines preferred as cover on the bench.
And Kellock admitted his omission from the side to face Pumas was tough to hear.
Writing in The Scotsman, Kellock said: "Andy Robinson took me aside on Monday and told me I was out.
"I knew he wanted to speak to me and hoped it would be about plans for Argentina, but he didn't beat about the bush.
"He said 'I'm not going to involve you this week', and in that moment the ground could have opened up.
"I want to say I was gutted, but that doesn't do justice to the feelings you experience at that moment."
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The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
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Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
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The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
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The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.
