Image source: Vanguard Natural Resources.

What: February was unkind to Vanguard Natural Resources (NASDAQ: VNR), though that's nothing new considering that its units are down more than 85% over the past year. While the persistently low price of oil is mostly to blame for that weakness, last month we can also point the finger at analysts as well as the company's credit situation and its delayed annual report for another double-digit slide.

So what: Analysts were pretty bearish on Vanguard Natural Resources last month with not one but three of them downgrading the stock. Raymond James and Bank of America both downgraded the company to underperform from outperform and neutral, respectively. Meanwhile, neutral was the downgrade destination of Landenburg Thalmann, which had rated it a buy before last month's downgrade. With oil prices continuing to remain weak, that's putting even more pressure on Vanguard Natural Resources' already weak finances, leaving analysts little reason to be bullish on the company.

The big concern right now is its credit facility. As of the end of last year, it had borrowed $1.69 billion of its $1.8 billion borrowing base leaving it with precious little liquidity. Furthermore, in April its banks are expected to redetermine its borrowing base with a very real risk that the borrowing base could be cut below the nearly $1.7 billion it already has borrowed. That would cause the company to scramble to come up with the cash it needs to pay back its banks to bring its facility back in compliance.

In addition to that, the company also announced at the end of the month that it was delaying the filing of its annual report. It said it needed more time to compile and integrate the financial statements of its recent acquisitions LRE and Eagle Rock after running into some unforeseen delays. That added even more uncertainty to the situation, which is something investors loathe to see.

Now what: Vanguard Natural Resources, like a lot of indebted oil companies, is in a tight spot right now because the clock is ticking on its credit facility. The risk is real that its banks won't be lenient, which could be a devastating blow for the company's liquidity. That has analysts and investors worried that it might not make it through the downturn without having to sell assets at fire-sale prices or, worse yet, be forced to restructure through bankruptcy.