But on Saturday they will be in opposing camps and Lamont has already shown his top class pedigree this season with two tries in Scotland's stunning victory over France.
Cohen is looking forward to locking horns with his club-mate and just hopes his inside knowledge can give England the upper hand as they chase a third straight Six Nations victory.
"Sean is a great player and I rate him big time. He is already a world class player and is getting better and better," said Cohen.
"There is no doubt that coming south of the border this season has helped him improve his game because the Premiership is a very tough league.
"With the likes of Carlos Spencer, Jon Clarke and Bruce Reihana, Sean is playing with backs who allow him to express himself a bit more."
Cohen and Lamont will be on opposite wings on Saturday, but such is their shared hunger for work there is no doubt they will clash at some point in the game.
Lamont scored his first try against France by showing the sort of acute eye for the try-line that will have had Cohen's wing partner Mark Cueto sitting up and taking notice.
His second showed his versatility as he played the role of loose-forward, joining a powerful Scotland drive before emerging with the ball and diving over.
"It would be good to be directly up against Sean on Saturday but I am sure we will bump into each other at some point of the match," said Cohen.
"When you are training and playing with a guy week in, week out, you get an idea of strengths and weaknesses and I am sure that is the same for Sean when he looks at my game.
"At Test level, we all do our own individual analysis about our opposite number and Mark will be doing that on Sean this week."