We're days away from the draft, and, while trades could happen before then (thanks, Flyers and Ducks, for starting with a banger), we're operating under the assumption that the St. Louis Blues will be making their selection at 19th overall. It's their only pick in the first four rounds, so trading it for immediate help would do quite a number on their prospect pipeline. So when the Blues make the pick, they should use it on a forward--preferably a center, but we can't be too picky.
There are a couple of reasons for this. We've written before that the Blues could consider drafting a goaltender, but realistically goalies take a number of years to even take on the role of an NHL backup; Joel Hofer didn't get regular starts until he was 23 years old and, given Joshua Ravensbergen's profile, we likely wouldn't see him in the NHL until he's 22 at the earliest. That's four or more years from now and doesn't much help the Blues through their retool. There's vision to drafting Ravensbergen, sure, but it doesn't seem to align with the timeline.
The Blues would likely have their pick of defensemen at 19th overall, as well. Several of Cam Reid, Logan Hensler, Blake Fiddler, and Sascha Boumedienne should still be available in the late teens, and there's always a chance that a more highly regarded defense prospect like Jackson Smith drops down the board. However, much like goalies, defensemen take quite a while to develop into impact NHLers. Sure, they probably enter the league earlier (maybe aged 20 or 21 for 1st-round prospects), but their youthful weaknesses can end up more exposed than forwards. Plus, the Blues already have a pair of promising defense prospects in Adam Jiricek and Theo Lindstein; picking another defenseman may be inadvisable.
That leaves the forwards. At 19th overall, there should be quite a few available, though how the board falls is anybody's guess. Carter Bear is recovering from injury, which may cause him to drop to the Blues, and Victor Eklund is a top-ten guy on talent alone, but he's on the smaller side. More likely, the Blues will have a choice of centers Cullen Potter, Braden Cootes, and Benjamin Kindel, who are all on the smaller side but make up for it in other aspects of their game. On the wing, the Blues might like the hulking Lynden Lakovic (who's been mocked to the Blues several times) or the high-effort, hard-working Malcolm Spence. While none of these players are likely to crack an NHL lineup next season, they could be contributors in short order--maybe two years, if we're being optimistic.
That's just from a consensus perspective, though. Because the Blues only have that one pick in the first four rounds, there's a chance they reach for a player projected to go late in the first round or even in the second round. If that's the case, you may as well throw a dart with your eyes closed and see where it lands--and if you happen to guess it correctly, maybe buy yourself a lottery ticket while you're at it.