Replace a lintel about the back door

[HOUSER1980]

All, tips and advice please.

I have a 1930s semi with solid 9ins brick walls.I am replacing my old wooden rear door with a upvc one. Whilst taking out the out the wooden frame ive notice the outside lintel is solid and fine. However the inner lintel, above the door is rotten and falling apart. Will it need replacing or is the outer lintel all I need?

Thanks

 

[pred]

Replace them both, the last one I did had a coarse of headers aver the lintel so if you remove the rotten one first and replace it with a 4x2 concrete lintel then the next day when the muck is dry replace the other lintel.