De Tomas has been in exemplary form for Espanyol in the last two seasons, helping them get promoted from the second tier by scoring 23 goals in the 2020/21 campaign.
Last season he helped his club achieve a comfortable 14th place finish by netting 17 goals in 34 La Liga appearances.
His impressive displays have seen him catch the attention of clubs this summer and he could be on his way out of Espanyol.
Fulham have made contact with De Tomas as they look to add to their striker options, according to Spanish radio station COPE.
The striker is said to be studying the possibility of moving to Fulham but he is also waiting for another club to make an attempt for him.
It is his intention though to leave the La Liga club this summer, with him having not made a single appearance this season.
His replacement, Joselu, has played every minute of the season and scored two goals and with De Tomas wanting to leave, he could be on the move before the window closes.