VIDEO: Major concern as Keith Earls suffers sickening blow to head against Leinster

Joe Schmidt must hate this time of year.

He's just six weeks or so out from getting his Six Nations campaign underway in a bid to win three championships in a row, and he's seeing his key players struck down with injury. Already Tommy Bowe is out, Mike Ross suffered a hamstring injury last week, and now there will be major fears for the health of Keith Earls. The Limerick man lined up against Leinster tonight in the inter-provincial derby at Thomond Park, but was taken off the field five minutes before half time after suffering what looked like a sickening blow to his head when he collided with Leinster's full back Zane Kirchner. Earls of course has a history of concussion which will be a major worry, but he did give a thumbs up as he left the field which hopefully will indicate that the injury is not as serious as first feared as Munster lost 24-7. https://twitter.com/Munsterrugby/status/681173594429353984 https://twitter.com/JMNeethling/status/681176820616683520 https://twitter.com/Gordonwdarcy/status/681173289637642240 Leinster prop Cian Healy also suffered a worrying injury as he limped off the pitch just over ten minutes after coming on as a substitute. Head coach Leo Cullen revealed that Healy had twisted his knee but would need further examination to learn the full extent of the injury. https://twitter.com/EnnyOrl/status/681189332036771840 https://twitter.com/Linda_Marie89/status/681189114876657664 https://twitter.com/MazzyRugby11/status/681191533232664577