The Arsenal striker picked up a nasty looking injury in the draw with Manchester City.
The forward has been in fine form in the second half of this campaign after battling back from a long-term injury.
That was seemingly curtailed on Sunday though, as he limped out of the clash with Manchester City with an apparent knee injury.
Arsene Wenger admitted after the game it looked a bad one, and if that is the case then Jenas says the news will be devastating to the England manager.
“It was a nasty one,” he told Match of the Day 2. “I would say if he does miss the Euros, this is one Roy will be absolutely devastated about because he’s a huge part of the way they play.”
Should Welbeck’s injury prove to be sufficient to rule him out of Euro 2016, it will certainly be a blow to England.
Aside from being a threat up front, he offers the ability to play in several positions, which is a major boost for any side in tournament football.
Another player who can do the same is Alex Oxlade-Chamberlain, but he is also missing now, limiting the Three Lions’ options considerably.
It could prove positive news for some though, with an injury ruling Welbeck out likely to be a big boost to the hopes of the likes of Daniel Sturridge and Andy Carroll.