The Nats signed a couple guys yesterday to minor league deals. These things are basically no-lose situations because if the guy isn't good enough you don't have to keep him and pay him. There's no real harm in filling out those extra spring innings with guys like this. All teams do this.
However, just because the individual deals are perfectly fine, that doesn't mean there isn't a negative spin to it. There are only so many Spring Training innings out there. If you want to evaluate Joe Nathan and Matt Albers and Vance Worley AND Tim Collins against even the vaguely "real" competition of a Spring Training game you start to lose innings that guys you know you want to keep need to get ready for the season. In other words - the more guys like this you sign, the less likely it is you sign someone that isn't a question mark. I don't think the Nats have gotten to that point yet but it's something to keep an eye on if you hear of more signings like this.
What about these guys?
Relatively few fans have the affection for Joe Nathan that I do. He's the best contemporary ball player from my neck of the woods. But let's be honest he's very old and a huge injury risk. To be more specific he is 42 and coming off his second Tommy John surgery. In the history of baseball only 81 times has a 42+ pitcher thrown 10+ innings of better than average ball. Since 2010 it's only been done 4 times. Is he any good to be bothering with even trying? Hard to say. He's has been decent since returning from surgery but had very limited pitching the past two seasons; 1 inning total in 2015, 21.2 innings last year. Neither the Cubs nor the Giants, two playoff contenders, saw him and thought they needed to keep him, so my guess is no. But we think Maddux likes him, so there's that
Albers is a a sinkerball pitcher who had a short stint of success and an even shorter stint of deserved success in the 2010s. He doesn't miss bats, and his control has mostly been poor, so his success lies completely in forcing GBs and getting a good BABIP. If he can do both he's passable, if not he's terrible. Since he seemingly had an epiphany in 2015 (Ks up, BBs down) that made him a better pithcer, it's worth kicking the tires, but his overall history and his recent one say the same thing. Pass
Worley is an underappreciated mediocrity. It's easy to look at his stats and see no reason to be interested. Like Albers he doesn't strike anyone out anymore and he's not particularly unhittable. But he has better control in general and he's usually not giving up a bunch of homers. While nothing from the last two seasons suggests a rebound is likely (everything is trending in a bad way with age) His age and his FB speed both suggest there is no reason to believe he suddenly will be a lot worse than he is. If you want to stash a guy in AAA who seems likely to be a inning eating 4.50+ ERA type, and the Nats can use someone like that, Worley fills that role perfectly.
Collins was a very good reliever for three+ years. He had untouchable stuff (9.7 K/9, 7.4 H/9 from 2011-2013) but was held back from elite status by control issues (5.2 BB/9). Then his arm blew. He got Tommy John but in what should be a cautionary tale for everyone that thinks TJ surgery will work perfectly, Collins felt discomfort during his rehab period and it was discovered that the TJ had failed. He would need another one. That is why he is where he is now. I can't really find any info on his rehab so far so it's all a big question mark. But someone was going to give him a chance with that arm. Oh he's also short! 5'7". So if you are a short guy who roots for short guys that's something.