The friendship will be put on hold when Phillips and the Lions visit Simon and his new club, the Saskatchewan Roughriders, in a key West Division matchup.
"I (played) with him for eight years and he's definitely been a great mentor, a great guy, a great teammate and a personal friend," said Phillips, a 30-year-old Seattle native. "Our families are connected and things like that.
"But, at the end of the day, once we get between those lines, Geroy's definitely the enemy. He's in the green and white, so he's definitely the opposition. So we've got to make sure we take him out and minimize him and make sure he makes no big plays — because I know he's looking forward to coming in and making a couple big plays against us."
B.C. (7-4) can move into a second-place tie with Saskatchewan (8-3), which has lost two straight. This will be the first meeting between the teams since Simon, who played 12 of his 15 CFL seasons with the Lions, was traded to Saskatchewan in January.
Following the 2012 season, Simon, 38, was open to restructuring his contract with B.C. but had said if the club didn't want him back he'd look at playing elsewhere. Lions GM Wally Buono gave Simon and his camp permission to gauge interest in a potential trade, and Jan. 24 the veteran was dealt to Saskatchewan for receiver Justin Harper, who showed up at an off-season offensive camp out of shape and was released, and a 2014 third-round draft pick.
Simon missed five games last season with hamstring issues, prompting suggestions about his durablility. And Simon missed Saskatchewan's first three regular-season contests with an upper body injury.
But with receiver Weston Dressler and running back Kory Sheets out of Saskatchewan's lineup with injuries, B.C. expects Simon to play a more prominent role than he has in earlier games.
"I anticipate him seeing the ball more, period, just because he was on our team for a number of years and he may have a little more knowledge of the things that we may be trying to do as a defence," said Phillips. "So I expect them to try to utilize him as much as possible."
Simon is the CFL's all-time receiving yards leader (16,128 yards) and needs just six more catches to break former Montreal receiver Ben Cahoon's CFL record of 1,017 career receptions.
"I just want to make sure he don't get that (receptions record) against us," said Phillips. "That's my biggest thing.
"He can get it eventually, but I want to make sure he gets, maybe, two (receptions), and make sure they're not for touchdowns or anything like that — because we definitely don't want to see him doing no poses or anything like that against us."
Simon is known for doing a Superman pose after scoring a touchdown. The Lions are out to make sure the Riders don't gain superiority because of Simon's knowledge of their offensive system.
"I know he's probably telling them everything in the book about us, just like we're gonna tell everything in the book about him," said Phillips. "That's something that goes a long way."
Phillips is also wary of what Simon can do in one-on-one matchups. Defenders must be patient with him, Phillips said, because Simon can set them up for mistakes that will lead to long gains.
"He's not at that stage anymore where he's going to just outrun you or anything like that," said Phillips. "But, obviously, his awareness and IQ of the game (are) unparalleled.
"There's nothing he hasn't seen before. There's not too many defences he hasn't seen before and things like that, so you're not going to fool him too much."
Simon's first encounter with his former club has been generating hype all week. He held a conference call Wednesday as the Roughriders attempted to accommodate more out-of-town interview requests than usual.
The Lions, meanwhile, have been fielding questions about Simon since Monday.
Sophomore defensive back Josh Bell, 28, said Simon's presence just adds "more coals on the fire" as the Lions get ready for an intense battle with the Riders for home-field advantage in the playoffs.
"I'm studying as much film as I can of Geroy," said Bell. "I learned a lot from him last year, being able to go against him on scout team every single day . . . but then he is, right now, the goat.
"But to be the best, you have to beat the best. So I'm going to be the best piece of the puzzle as possible."
Simon isn't the big piece of an offence that he used to be. He's the Riders' fourth-leading receiver with 23 receptions for 341 yards and three touchdowns. But Lions coach Mike Benevides knows the Johnstown, Pa., native can still puzzle the opposition with his moves.
"I got to see him work through his craft," said Benevides. "You can't stop him. He's got enough experience. He knows exactly what it is he needs to do and certainly, he understands us, too.
"So (defending him) is going to be a challenge."
NOTES: The Lions worked out with crowd noise pumped in Thursday to simulate the loud conditions they'll likely face at Mosaic Stadium before the Riders rabid fans.