Kranjcar has had limited first-team opportunities this year and his future at the club was thrown into further doubt with the signing of Steven Pienaar from Everton.
Redknapp revealed last week that Kranjcar had his heart set on leaving the club and admitted today that Bremen had lodged a bid for the 26-year-old, but doubts that he will leave the club.
"There is a German club (Bremen) that have come in for him. They have offered good money for him but I'm not keen to lose Niko,'' Redknapp said. "He is a good player, a fantastic player.
"I don't think he wants to go to Germany and play. I don't think he feels that's an option for him. If that's the case then he will stay here and that's great for us as well.''
Redknapp denied that Everton, who have been linked with the midfielder, have also made a bid. With his team fighting for honours on three fronts this season, Redknapp hopes the man he signed from Portsmouth in 2009 will play a key role in the remainder of the campaign.
"We have a lot of games coming up. We are going to need a squad," Redknapp said. "There's talk that the Sunderland game that we have coming up could be an evening kick-off on a Saturday and then Tuesday we play AC Milan away, then we have them at home.
"These games are going to be coming thick and fast. We have a rearranged game with Blackpool to play on a Wednesday night. It's going to be Saturday, midweek, Saturday, midweek. Niko is going to be an important player for us.''
Fulham boss Mark Hughes has denied Fulham are hoping to recruit Kranjcar. The Cottagers had reportedly turned their attention to Kranjcar following the collapse of their attempt to sign Manchester City winger Shaun Wright-Phillips but Hughes has denied the claims.
"We're not interested in Niko," Hughes said. "We've got a lot of midfield players and he's not a priority for us,'' he said. We've expressed an interest in Shaun. It's slowed and I'm not too hopeful. We tried to make it happen but for a number of reasons it seems to be less likely as the window closes.''
Hughes also stated that Paul Konchesky is unlikely to return to Craven Cottage this month after joining Liverpool last summer.
"There was interest and discussion was mooted, but that's not likely to progress in this window,'' he said. "It's something we may revisit but it won't happen this month.''