Morgan has been ruled out for the rest of the season after suffering knee ligament damage in the defeat to Worcester.
The injury to the 26-year-old had left Gloucester short of options in the No.15 shirt - opening the door for a return to English rugby for Phillips.
The former Newcastle back had been a free agent following his departure from Stade Francais in the summer after two years at the Parisians.
A knee injury initially hampered Phillips' hunt for a new club - although Northampton, Leicester and Toulon were all monitoring his progress.
But having returned to full fitness, the 29-year-old former IRB World Sevens player of the year has now agreed to move to Kingsholm until the end of the season.
Phillips, though, will have to wait to make his debut with Gloucester involved in the final two rounds of the Heineken Cup pool stages.
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
$29.99
The All Blacks Performance t-shirt is black with hints of blue from the training jersey. Very Cool.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.