Guimaraes, who is Newcastle's top scorer in the Premier League this season with nine goals, has been pushing to come back as soon as possible, Howe told reporters on Friday.
"The medical team are trying to hold him back ... I say hold him back, there's always that tug because the player is desperate to play and I love that with Bruno," the manager said.
"I'll make a decision based on what I see in training today, but there is a chance."
Brazil midfielder Guimaraes played a key role for his country during the World Cup qualifiers, and the injury saw him miss this year's friendlies against France and Croatia ahead of the tournament starting in June.
However, the 28-year-old's form before his injury has sparked media speculation of a potential move to Real Madrid or Manchester United in the close season.
Newcastle's England forward Anthony Gordon, who has 10 goals in the Champions League this season, has also been linked with several clubs, including Bayern Munich, Liverpool and Arsenal.
But Howe said he wanted players fully committed to the club and Newcastle's future despite the transfer talk around them.
"The biggest thing I look for is the commitment to training ... I won't play a player if I don't think they are 100% committed to the club and its future. I'm not talking about Anthony here, I'm talking generally across the board," he said.
"When they're high profile, like the ones we have here, they're in the news all the time for lots of different reasons.
"It comes with the territory. You have to adjust and adapt to it, you have to understand to it, and try to play to your best level with the noise around you.
"I don't think you get to this level without the ability to do that. I don't think any player can use that as an excuse towards lower performances. The lads internally aren't."