I did sprain my calf a few years ago.  But I took 7 weeks off and came back with no problem.  It's strange to have it come back after such a long time off, unless you were pushing too hard or just got unlucky.  I have seen one article which seems to have helped several people.  Maybe it will help you too - link below.

http://www.thestick.net/Articles/Calf_%20Heart_%20Attack.htm

Len

While the Stick may help maintain your calf muscles, and the   manufacturer is aware of the power of massage, there are times when more   focused pressure is more appropriate. Muscles with injured portions   that result in mini-spasms (aka "trigger points," referred to in the  article as "knots" around micro-tears)  can be very persistent as you  have found, and often cannot be rested  away, even lasting a lifetime in  extreme cases. In fact, trigger points  have been photographed in fresh  cadavers.. It's hard to get more relaxed  than that, yo.

Consistently  rolling over a trigger  point with a stick or foam roller may bring  results in easier cases, but  for a persistent trigger point you need  more focused pressure. It may  "laugh" at anything less, even get worse  from the irritation. At the  very least you may waste precious time. Sit  in a chair and prop your leg  up where you can easily get to the rear  calf with your thumbs. Probe  the entire length of the layers of muscle  here for sensitive spots, some  of which can be invisibly small,  comprised of only a few mutinous  fibers. It is here that focused  pressure, delivered in a series of  short, few-second applications, can  bring near-instant relief to trigger  points. On the other hand,  spreading the pressure over a broad area  with a roller can de-fang your  approach. Deep points need deeper pressure, or they will not be  deactivated. I know because I work on them for a living.

The  longer trigger points have persisted, the more  likely they are to  return, which is why you want to repeat this  treatment a few times a  day for the days, weeks, or months it may take  to re-educate your  neuromuscular system. Just as old habits are hard to  break, ingrained  patterns of pain and discomfort are a well-worn pathway  of  neuromuscular discomfort that is frequently revisited until your   persistence has banished it to history. Damage to the muscle in question   is not always the cause. Sometimes they are due to damage in a   neighboring muscle that has shifted the workload next door.

When  you've taken care of the more acute problem(s),  by all means return to  the tool of choice for general flushing and  circulatory maintenance -  but if you must roll, please roll in  the direction of the heart  to protect your veins and lymphatic system,  which are fitted with  one-way valves for this purpose. Otherwise, you  risk damage to both.  I've seen entirely too many people use the Stick in  this improper way,  and the sales lit, all manuals and articles of  reference should always  mention this, but don't (it should be embossed  on the tool itself). I  use my own soaped hands in the shower for the  same purpose, with more  definition and control, not to mention  portability. I own a Stick,  which has been gathering dust in my living  room for nearly 10 years. I  find it too hard for comfort, and too flat  and blunt for detail work on  curved and multi-faceted muscles. Though  there are knobbier versions  that improve the experience, I wouldn't risk  a Boston Qualifier for it  no way, no how, or I might be using one professionally to rest my  thumbs.

Here's a tool that lets you strip away and view the layers of muscle...

http://www.getbodysmart.com/ap/muscularsystem/footmuscles/soleus/tutorial.html

You will find that more permanent objects like subcutaneous cysts,  varicosities, etc. tend to stay put, while a rrigger point is a  spontaneous phenomenon that tends to move around. It may even disappear  as you press on it, which of course is your goal. They tend to occur at  familiar locations, though, which correspond to points in the muscle  that are more vulnerable or closer to motor nerve entry. I liken them to  circuit breakers that occasionally trip and need to be reset. Otrher  things to look out for are arteries, which throb, and nerves, which may  produce a more painfully electrical sensation.

A  trigger point will often hurt but feel the need for more pressure. They  are more active electrically than surrounding tissue and can be detected  by sensitive equipment and visualized by specialized MRAs. Once  deactivated, they should reappear with decreasing frequency if you  handle them promptly, unless there is a biomechanical or environmental  issue that continues to irritate the host muscle.

Although  tools like tennis balls, golf balls, Sticks, etc. seem safer at first,  you will eventually become more comfortable with your thumbs because of  the tactile feedback and level of control. Frequency of application  depends on how much the area is bothering you, but prophylactic  treatment would begin with once a day. I work my calves/achilles area  with soaped fingers in every morning shower. If something is really  bothering me I will get on it as frequently as I feel the need, but  rarely more than 3-5 times a day. A session of trigger-pointing an area  seldom takes longer than a minute or two, and most serious problems  become manageable within a few days to a few weeks if not immediately.  In rare cases a few months are required, especially after years of  dysfunction.

I am not surprised you calf has quieted  down, but you now have another tool in your kit to make sure it stays  that way, even after your level of training increases. Good luck with  your running!