Spurs striker Defoe earned an international call-up for the game in Sweden on Wednesday and of course swapped places with Bobby in January, beating the deadline to allow him to fulfil a lifelong dream of playing for the Hammers.
"He is a top class striker and I wish him all the best - I would love to be playing alongside him," he says.
"But we have to look after ourselves and I am a West Ham player first.
"I have to make sure we get in the Premiership and then we can think about other things in the future."
Bobby was delighted to get back to winning and scoring ways against Gillingham on Saturday and adds:
"It was a good effort by all the boys and we were just disappointed to only get two, really.
"But we created a lot of chances - and that is a positive thing.
"Their keeper pulled off a few good saves from me and others, including Christian Dailly, and he was on fire, to be fair."
Did the previous week's Millwall defeat hit him harder as a fan as well as a player?
"Yes, definitely; a lot of my friends said 'what happened?' and it was just one of those days," he admits.
"I don't think we put in the performance that we should have; every single one of us has held our hands up about that.
"We were disappointed but at the same time maybe it came at a 'good' time because it was a shake-up for the big run-in; we have to knuckle down to put in some good performances week in, week out - now is the time to do that."
Bobby will be reunited with his former manager Steve Coppell, now in charge of Reading, at the weekend, and he is full of praise for him.
"He looked after me at Brighton and did a good job; he is a very good manager and I am sure he will put out a strong side on Saturday.
"I had a couple of injuries, he made sure that I was well treated, and he taught me a few things one on one."
He aims to put one over his old boss, of course, and insists he has not given up hope of a place in the top two.
"There is definitely still a chance of the top two; it is obviously mathematically possible and we are gunning for it."