At 28-12, the Houston Astros have the best record in all of baseball at the moment. Their plus-58 run differential is second best in MLB. The Astros have won three straight games and 13 of their last 16 games overall. Red hot would be an understatement.

As good as they've been so far this season, the Astros are open to adding pieces prior to the trade deadline, and that isn't surprising at all. Resting on your laurels is no way to go through the season. There is always room for improvement and Astros general manager Jeff Luhnow recognizes that.

Ken Rosenthal of Fox Sports has some details on Luhnow's shopping list:

The Astros remain interested in adding a starting pitcher and also are likely to pursue a left-handed reliever before the July 31 nonwaiver deadline, major-league sources say.

Those are two pretty common "wants" prior to the deadline. Lots of teams are looking to add a starting pitcher and/or a lefty reliever. The Astros are no different.

Astros GM Jeff Luhnow is said to be looking for a starting pitcher and a lefty reliever. USATSI

Rosenthal mentions the Pirates, who are in last place in the NL Central, as a possible trade partner for the Astros. Gerrit Cole's name has come up in trade rumors the last few weeks, and lefty closer Tony Watson is due to become a free agent after the season. It only makes sense to listen to offers for him.

The Pirates are not the only team that could offer the Astros both a starter and a lefty reliever in the same trade, however. Here are some other potential trade partners, which an emphasis on teams either already out of the race or potentially fading out of it, who could satisfy Houston's needs.

Atlanta Braves

The Braves added three low cost veteran pitchers over the winter, all on one-year contracts, and they figure to market them all to pitching needy teams at the trade deadline. The only problem is Bartolo Colon (6.80 ERA), Jaime Garcia (4.33 ERA), and R.A. Dickey (4.22 ERA) aren't pitching all that well. Would the Braves listen on ace Julio Teheran? I'm guessing the Astros would love to add him to their pitching staff.

As for the lefty reliever thing, the Braves could offer Ian Krol, who has ugly numbers overall (7.63 ERA) but is holding left-handed batters to a .208 batting average in 2017. Atlanta feels like more of a last resort trade partner. If the Astros strike out everywhere else, they could turn to the Braves to acquire a starter and lefty reliever for depth, but unless Teheran is involved, they would't be getting an impact piece.

Chicago White Sox

Over the winter the White Sox and Astros were connected in trade rumors on a near daily basis thanks to lefty Jose Quintana. He is very much available now that the ChiSox are in the middle of a full rebuild. The problem? Quintana has a 4.38 ERA so far this season. It's been a down start to the season for him. Quintana is better than that though, and the Astros could look to bring him in anyway given his cheap long-term contract.

The White Sox have a quality lefty reliever to offer in Dan Jennings. Lefties are actually hitting .348 against him in the early going this year, though that's more small sample size noise than anything. Last year he held left-handed hitters to a .217 average. Not the sexiest name, no, but Jennings is someone the Astros could consider acquiring as part of a Quintana trade.

Kansas City Royals

Tuesday night's loss snapped the Royals' modest four-game winning streak, though they remain in last place in the AL Central at 16-22. Kansas City has a small army of impending free agents (Eric Hosmer, Mike Moustakas, Lorenzo Cain, etc.), so if they don't turn things around soon, general manager Dayton Moore will have no choice but to consider a trade deadline fire sale.

One of those impending free agents is left-hander Jason Vargas, who owns a 1.01 ERA in seven starts and 44 2/3 innings this year. He's been phenomenal. Vargas isn't really this good, we know that, but he has been a rock solid midrotation starter for the last half-decade or so. My guess is the Astros would prefer young Matt Strahm to either Travis Wood or Mike Minor for the lefty relief job. Strahm allowed seven runs in his first 1 1/3 innings this year, but he's been lights out since.

Oakland Athletics

The Athletics are another last place team that figures to shop veterans at the trade deadline. Sonny Gray recently returned from a lat injury and has been so-so in three starts so far (3.78 ERA). At his best, Gray is a bona fide ace, and the fact he is under team control through 2019 will appeal to the Astros. They could look to buy low on Gray and pair him with Dallas Keuchel and Lance McCullers Jr. going forward.

Sean Doolittle is currently on the disabled list with a shoulder issues -- he's had lots of shoulder issues the last few seasons -- which makes him a risky investment as a left-handed reliever. The Astros could instead take a look at the lesser known Daniel Coulombe, who has held same-side batters to a .207 batting since the start of last season. Coulombe would be a nifty little pickup for a contending team given his success against lefties.

San Diego Padres

Unlike the other teams in this post, the Padres have no shortage of quality lefty relief options. Both Ryan Buchter and Brad Hand are excellent strikeout heavy shutdown lefties who would be an upgrade for nearly every team. Both come with multiple years of team control as well, so they're not rentals. I'm certain the Padres will field trade offers for both in the coming weeks and months.

The starting pitcher situation is much more dicey. Is Trevor Cahill (3.27 ERA) for real? Or is this just a hot start? Clayton Richard has become an extreme ground ball pitcher (58.9 percent), though it hasn't helped him keep runs off the board (4.86 ERA). If Cahill keeps this up, which is a very big "if" right now, acquiring him plus Buchter or Hand could be Houston's best course of action aside from a monster Cole/Watson deal.

Toronto Blue Jays

The Blue Jays might be coming out of their early season funk. Might. They have lost their last two games, but, prior to that, they won five straight and seven of their previous eight games. It's something. Toronto remains in last place in the AL East at 17-23, and if they're going to get back in the race, it has to happen soon. The losing streak must stop at two.

However, if the Blue Jays do continue to slip out of the race, general manager Ross Atkins could peddle impending free agent Marco Estrada (3.11 ERA), who has very quietly been one of the best pitchers in baseball since arriving in Toronto three years ago. The lefty relief situation is up in the air. J.P. Howell hasn't looked good in limited time and Aaron Loup is no one's idea of a shutdown left-on-left guy. What about Francisco Liriano as a reliever? That'd be interesting.

Keep in mind it is still relatively early in the season, too early for serious trade discussions to begin. Not many teams are ready to throw in the towel and sell yet. That usually doesn't happen until after the amateur draft in June and closer to the July 31 trade deadline. You can be sure the Astros will be doing their homework in the meantime, of course. They'll have eyes on Cole, Quintana, Cahill, Estrada, and basically every potentially available pitcher between now and the trade deadline.