2. Mario Yepes
Current Club: Unattached At 38 years old, the former Paris St Germain and Milan defender would hardly be a long-term solution, but he is another of those older players defying the ravages of age to prove that ability lasts longer than some might think. The Colombuan was supposed to retire immediately after the World Cup, but his imperious performances for the South Americans - which marked him out as one of the best defenders in Brazil - obviously gave him a new lease of life. After playing Uruguay, the defender told reporters that he doesn't yet feel his age, and his performances vouched for the same fact. That could be a good thing for Celtic, who should look into adding his experience - but more importantly his ability - to the back-line ahead of their potential participation in the Champions League group stages.