Proving Ground introduces a brand new effect within the Transfer screen called Transfer Focus. While Transfer Focus is active all featured players of the current theme bought through Auctions, Scout, Assistant or Recommended tab in the Transfers will come with an increased attribute.
This attribute is permanent and will remain beyond the season. You can check which attribute will be increased by visiting the player screen - it will be highlighted in a special color.
Keep in mind that the Negotiations tab is not affected.