Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: Amid the flurry of tributes that followed Al Kellock’s announcement he was retiring at the end of the season, one from another old warhorse stood out. ‘So my friend and foe Alastair Kellock calls time on a great career,’ tweeted Scotland and Saracens lock Jim Hamilton. ‘Been a pleasure punching and getting punched by you. And punching together.’ As he suggested, Hamilton had stood toe to toe with his countryman as opponents when their respective teams, Edinburgh and Glasgow, clashed. But, in the second row for Scotland, they would have each other’s backs as they fought — normally against the odds — for their country.Glasgow Warriors captain Al Kellock will retire at the end of the seasonKellock amassed 56 Scotland caps during eleven-year international careerThe lock is calling time on career after 150 matches as Glasgow captain 
 Question:‘_ has put his body on the line a lot during his nine years with the club and he’s still competing very hard with the other second-rows to be selected ahead of them.

Al Kellock