Says Steve: "What the fans have got to realise is that he was a young lad coming through and he doesn't owe the club anything. Obviously the club gave him a chance and he has repaid it with the £11m.
"That is forgotten. At the end of the day there have been plenty of players that have come through and not done half of what Frank has done, and he has produced a hell of a return.
"Because he is a homegrown player and his dad is who he is, he is going to get a bit of stick but I still think everything has equalled out."
Some supporters have been surprised by comments attributed to Frank in the build up to the games between the two clubs in recent weeks, but Steve insists there are no hard feelings.
"I got on with both Franks and there are no grievances whatsoever," he says.
"Young Frank worked hard at his game to improve and he should be admired for that.
"Frank senior has played something like 700 games and that has been a fantastic achievement.
"The West Ham fans will give Frank a bit of stick but deep down they understand that he and his dad have given a lot of their life to West Ham."
Young Frank says that his family and friends have converted to Chelsea now, but Steve is surprised by that.
"His dad's a Chelsea fan?
"I don't know about that, but like any father he wants to see his lad do well and I don't think you can fault him for that.
"The problem is Frank had to follow his dad and there were always going to be labels of nepotism."
Frank senior is once more expected to attend the game - as he did at Upton Park earlier in the season when the two sides met in the league - giving lie to a newspaper report that claimed his family felt unable to go to Upton Park.
Adds Steve: "I think overall they have both served the club very well and they should be welcome - but if he gets a bit of stick and it puts him off his game then all the better!"
Looking at that win over Chelsea in the league in October, Steve admits the side rode their luck, and says: "I thought if you looked at the overall balance they could have said they were a bit unlucky. Shaka had a particularly good game that night but we got ourselves in the lead then worked really hard to keep it intact.
"They are usually pretty tight games, decent ones, with only a goal here or there - and I can't see this being any different.
"They have got a lot of players that can change positions, Zola and a couple of lads that can get a handful of goals, and a good midfield, so it will be difficult."
As for his own situation since returning from injury, he says: "I'm just glad to be playing and everything is a bonus, to be honest.
"I'm just trying to do myself justice in each game and I'm not looking beyond that. I haven't really trained that much at all because of the games so it has been pretty hectic.
"It is just basically trying to get through the games as best I can to try and do the team justice.
"Hopefully that will happen but if it doesn't he will have to take me out of it for a bit, but hopefully I can keep going and stay in there for a few games.
"It is usually pretty good under the lights at West Ham and I hope we can do it inside 90 minutes and save the extra time and penalties.
"I am just relishing being back playing and having that pressure to play."
And of the win over Blackburn he says: "It was a good win and we were comfortable in the end, but David James still had to make a couple of good saves that can change games.
"Blackburn have got a lot of talent going forward and a good attacking presence, so we had to keep going and it was good from that aspect.
"We put pressure on ourselves a little bit by not doing the business away from home again.
"So we have another big game tonight and then another game on our travels to try and put the away form right.
"It has pretty much been talked about until we are blue in the face but we have to get it psychologically out of our heads and go for it."
He feels that the Hammers have the resources to get through the final third of the season in the light of Glenn Roeder's assertion that there are unlikely to be any more purchases this season.
"We have got a thin squad but there are a lot of good players that can't get in the squad at the minute," he says.
"Scott Minto did very well when he came in earlier and with Ian Pearce coming back it will be good to see him play again."