The influence Russell Martin has on MK Dons cannot be measured, according to boss Paul Tisdale.
The 33-year-old signed from Walsall in January, and after helping Dons to promotion to League One, was deemed the best signing of the season by the manager.
Martin has continued to lead the defence this season, sitting out just one of their opening nine games this season - the 2-1 defeat to Accrington Stanley.
Having racked up more than 500 career appearances, playing in the top flight and on the international stage, Tisdale said Martin's ability to read the game is one of his best attributes.
"Right place, right time, thinking the right thing, and the last bit is the most important thing," said Tisdale. "When someone has the experience he has, and plays the way he does, it is intangible sometimes, the effect it has. You can see Sam Nombe's pace and power, but someone being in the right place to prevent something happening, picking up the pace or slowing it down, sometimes you can't see it, but you feel it as a manager.
"An opportunity arose to sign him, and I knew he was the right type. It helps that he plays so well, gets on with everyone and has experience. It has turned out to be a good signing because we had an up-and-down injury record with centre backs, but he was a constant throughout.
"David Kasumu, playing 15 yards in front of him, you can't quantify the influence that has on a young player, thinking the right thing, doing the right thing too. It's so important."