TAMPA — The Lightning still doesn't consider Jonathan Drouin's upper-body injury serious, but the touted wing prospect could be sidelined at least the rest of the week, and maybe longer, after showing no improvement.Drouin, 19 who hasn't practiced the past three days, was set for additional testing Monday, with the team expecting a clearer indication today of how long he'll be out. Coach Jon Cooper indicated it could be as much as two weeks.The Lightning host its first exhibition tonight, then plays Thursday in Nashville and Friday at home against Dallas.Drouin, the No. 3 overall pick in 2013, is expected to make the team, so this is a big camp. But Cooper doesn't appear overly concerned. Drouin has skated on his own the past two days."What's bothering him, once it gets better, it won't bother him again," Cooper said. "It shouldn't be a long-term lingering thing."Oh captain: C Steven Stamkos, who had a planned day off Sunday, was back Monday and participated in the scrimmage, saying he felt really good. Stamkos, coming off a surgically repaired right leg, said he'd like to get into three of six preseason games. He won't play tonight."We're really happy with where he's at," Cooper said. "Clearly, he's got much more jump, confidence than he ever had during that last stretch of the year when he came back after the injury."LW Alex Killorn, C Valtteri Filppula and RW Brett Connolly will be the top line tonight, with D Jason Garrison also playing. For the full Lightning lineup, go to tampabay.com/blogs/lightning/.Go blue: Team Blue beat Team White 3-1 in Monday's scrimmage, with Killorn picking up two goals and Garrison one. LW Henri Ikonen scored for the White team.Contact Joe Smith at [email protected] Follow @TBTimes_ JSmith.